<PAGE>

                                                                  EXHIBIT 10.2.2


                               SECOND AMENDMENT
                                      TO
                         AGREEMENT AND PLAN OF MERGER

     This Second Amendment ("Second Amendment") to the Agreement and Plan of
                             ----------------
Merger, dated May 9,1999, as amended by the First Amendment to Agreement and
Plan of Merger, dated July 2, 1999 ("Agreement"), is made and entered into this
                                     ---------
24/th/ day of August, 1999, between MADISON RIVER TELEPHONE COMPANY, LLC, a
Delaware limited liability company ("Buyer"), and GULF COAST SERVICES, INC., an
Alabama corporation ("GCSI"). All capitalized terms not defined herein shall
have the meaning as set forth in the Agreement.

     WHEREAS, the parties have entered into The Agreement; and

     WHEREAS, pursuant to Section 5.1 of the Agreement, on June 2,1999, GCSI
delivered its Disclosure Schedules to Buyer; and

     WHEREAS, pursuant to Section 5.1 of the Agreement, on June 21, 1999, Buyer
delivered its objections to the Disclosure Schedules to GCSI, and on July 27,
1999, Buyer delivered its restated objections to the Disclosure Schedules to
GCSI; and

     WHEREAS, the parties wish to amend the Agreement to further define certain
understandings and obligations of the parties.

     NOW, THEREFORE, in consideration of the promises and mutual covenants and
agreements contained herein, and other good and valuable consideration, the
receipt and sufficiency of which are acknowledged, Buyer and GCSI hereby amend
the Agreement as follows:

     The Agreement is amended by replacing the defined term "Merger
Consideration" in Article I with the following:

          "Merger Consideration" means the sum of (i) $3 10 million reduced by
     (A) Adjusted Long Term Debt as of the Closing Date, (B) the excess, if any,
     of S 17,3 94,3 47 over the capital expenditures of GCSI for Group I Fiber
     Projects (paid or recorded as a liability), made after December 31, 1998
     and on or prior to the Closing Date and (C) $1,679,553, minus any unjust
     enrichment penalty paid by GCSI or its Subsidiaries on or before the
     Closing Date with respect to the LMDS license (call sign WPOH618), (ii) the
     sales price of the Non-Business Real Estate as provided in Section 6.9, and
     (iii) the sales price of the DigiPH Stock as provided in Article IX.

     The Agreement is amended by deleting Section 5.1 and substituting the
following in lieu thereof:

          (a) The Disclosure Schedules delivered by GCSI to Buyer, as modified
     and supplemented through the date of this Second Amendment, have been
     reviewed and,
<PAGE>

     except as hereinafter provided in this Section 5, 1, the items and matters
     identified on the Disclosure Schedules as submitted to Buyer through the
     date hereof are hereby accepted by Buyer. The Disclosure Schedules are not
     accepted to the extent that any matter disclosed therein creates between
     the date hereof and the Closing Date a breach of any warranty,
     representation or covenant not known by the parties as of the date hereof.

          (b) In conjunction with Buyer's review of the Disclosure Schedules,
     GCSI agrees to pay, or cause to be paid by its Subsidiaries, prior to
     Closing and prior to the calculation of cash and cash equivalents of GCSI
     and its Subsidiaries as of the Effective Time, or by the Paying Agent
     pursuant to Section 2.6(d), the following: (i) any and all termination
     penalties or other payments owed to Computer Enterprises, Inc., pursuant to
     tile Agreement for Consulting Services, dated February 23, 1999, and listed
     as Item 20 on Disclosure Schedule 3.6, and as Item 6 on Disclosure Schedule
     3.7; (ii) any and all excise taxes, penalties and interest owed under
     (S)(S) 4962 and 4979 of the Code with respect to the Benefit Plans and
     listed as Item 4 on Disclosure Schedule 3.7; (iii) any and all fees for
     corporate finance services due and owing by GCSI to Joseph Decosimo and
     Company, Certified Public Accountants, pursuant to that certain engagement
     letter dated May 4, 1999, and accepted on behalf of GCSI an June 2, 1999;
     (iv) any and all federal and state taxes shown as due and owing on the
     income tax returns of GCSI and its Subsidiaries for calendar year 1998, as
     well as federal and state estimated tax payments in amounts sufficient to
     cover such taxes of GCSI for estimated income through the Closing Date; (v)
     any and all fees for Year 2000 remediation efforts, or accounting or
     consulting services, incurred in connection with computer and related
     systems and software due and owing by GCSI or its Subsidiaries to Ernst &
     Young; and (vi) any and all fees for construction of the new GCSI
     administrative building due and owing by GCSI under all applicable
     construction agreements, minus any applicable retainage not to exceed five
     percent (5%) of the aggregate contract price as disclosed to Buyer through
     the date hereof.

          (c) GCSI acknowledges: (i) Buyer has not accepted Item 140 under

     "Material Contracts of GTC" on Disclosure Schedule 3.16 and Item 2 on
      -------------------------
     Disclosure Schedule 3.19, both of which arise out of the provision of
     Enhanced Universal Emergency Number Services by Gulf Telephone Company to
     the Baldwin County Emergency Communications District; (ii) Buyer does not
     consent to the sale, transfer or liquidation after the date hereof of any
     assets of GCSI and its Subsidiaries as proposed in the Disclosure
     Schedules, including, but not limited to, the sale of any additional shares
     of the common stock of Wireless One; and (iii) Buyer does not waive any
     breach of a material representation, warranty or covenant resulting from
     (A) any encumbrance or restriction on transfer affecting the GCSI Shares
     disclosed in the summary stock register and stock certificates, including,
     but not limited to, any option of the ESOP to acquire certain shares from
     the John McClure Snook Irrevocable and Testamentary Trusts, and (B) any
     corporate act or failure to act reflected in the minute books for GCSI and
     its Subsidiaries and any other matters disclosed therein which were not
     referenced in the Disclosure Schedules. Buyer does not waive any right to
     claim a breach of a representation, warranty or covenant contained in the
     Agreement relating to the level of trade payables as of the Closing Date.
<PAGE>

          (d) GCSI and Buyer agree that Buyer will, in good faith, reasonably
     attempt to obtain, at its expense, title insurance to cover the Real
     Property listed on the Disclosure Schedules, and to the extent that Buyer
     receives coverage over any matters that constitute, or could constitute,
     defects in the good and marketable title to the Real Property, other than
     Permitted Liens, Buyer will accept such matters relating to the Real
     Property. To the extent affirmative coverage cannot be reasonably obtained
     for such matters without the payment of money other than that required to
     pay for the title insurance policy(ies), Buyer does not waive any potential
     breach of the representation and warranty in Section 3.8 relating to title.

          (e) Notwithstanding anything in this Agreement to the contrary, the
     mere inclusion of an item in tile Disclosure Schedules as an exception to a
     representation or warranty shall not be deemed an admission by GCSI that
     such item represents a material exception or material fact, event or
     circumstance or that such item has had or could be reasonably expected to
     have a Material Adverse Effect.

     The Agreement is amended by deleting clause (iv) of paragraph (e) of
Section 7.1 in its entirety.

     IN WITNESS WHEREOF, the parties hereto have executed this Second Amendment
to the Agreement on the date first written.


MADISON RIVER TELEPHONE             GULF COAST SERVICES, INC.
      COMPANY, LLC


By:  PAUL H. SUNU                   By:  MARJORIE Y. SNOOK
     -------------------------           -----------------------------
Its: Managing Director & CFO        Its: President & CEO
     -------------------------           -----------------------------


Attested by:                        Attested by:


BRUCE BECKER                        ROBERT H. YOUNCE
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