Product: Debt collection

I am disputing charges from XXXX from XX/XX/XXXX which has recently resulted in a negative report to my credit record. I am requesting that the entry made to my credit records by collection agency 'Midland Credit Mgmt Inc ' as a result of initial fees from XXXX, be removed immediately. 
XX/XX/XXXX I switched to XXXX after having been with XXXX XXXX XXXX for over fifteen years. With no exaggeration and with the sales rep at their store being witness, the XXXX XXXX dropped XXXX of XXXX calls. I have confirmed with a XXXX rep who recently reviewed the notes on my account that the XXXX notes for my account reflect the following : XXXXXX/XX/XXXX After multiple trips to the XXXX store and multiple changes/updates/attempts to fix the issues, the equipment was returned to their XXXX Ohio store. 
( My note : I tried to return the equipment to the XXXX store in the 'Shops at XXXX XXXX ' which is only XXXX miles from my home a few days earlier but the manager ( I believe her name is XXXX ) refused to accept them and insisted that returns need to be made at the store they were purchased from. She and I had words, and I returned them to the XXXX store XXXX miles away. ) XX/XX/2012 {$800.00} credit, store confirmed equipment returned. 
XX/XX/XXXX {$440.00} credit for 'ETF ' but the note also states that there was a {$160.00} unpaid usage charge ( My note : When I returned the phones, I reviewed how I had made multiple trips to the XXXX store to allow XXXX to attempt to fix the problem. In addition, I expressed great concern that my clients were not happy with me due to the constant dropping of calls and my need for reliable mobile service. The further exasperate the problem, it infuriated me that I was forced to drive back to XXXX one last time to return them when I had a store XXXX miles from my home. I was told that ALL charges would be adjusted, including usage since the equipment and service was so terrible. 
XX/XX/XXXX notes that 'adjustments will be made to account because store rep confirmed return and cancel. ( My note : this should have specifically referred to the usage 'adjustment '. ) XX/XX/XXXX notes that there is a new bill for XX/XX/XXXX and XX/XX/XXXX available on XXXX. 
( My note : If I am NO LONGER A CUSTOMER how and I supposed to access mytmobile.com to know that there was a bill?? Until XX/XX/XXXX I was under the understanding that what I was TOLD by XXXX was true, that all charges had been adjusted off.!!! ) ( My note : XX/XX/XXXX I received a call from Midland collection co regarding this outstanding balance of {$180.00} to my surprise! Because I have been watching and protecting my credit rating, I agreed, ONLY IF NO POSTING TO MY CREDIT REPORT WAS MADE, to pay part of the balance. ) Summary : -The charges were supposedly adjusted off by XXXX per what I was told by XXXX-If the charges were not charged off, I should have been contacted prior to a collection agency calling me in XX/XX/XXXX and it being reported to my credit report. 
- If Midland reviews the recorded call this XX/XX/XXXX, the recording will make it evident that I only paid partial just to make the issue go away and NOT show on my report!! I request that any related postings to my credit report to any credit reporting agency, be removed completely and immediately.