Complaint sub-issue: Can't stop withdrawals from your account

Citibank has been charging illegal monthly federal tax withholding for the past 12 years on 2 of my linked accounts and another account with a separate login. I have fulfilled the w-9 form obligation a minimum of 7 times : 3 by mail ; 2 by branch locations ; 2 by fax. I am a US citizen, therefore the this is an unlawful collection of tax on multiple accounts. 

The most recent interactions : XXXX XXXX, employee ID XXXX Instructed me to download the W-9 from IRS website XXXX and mail to : Citigroup Technology Inc XXXX XXXX XXXX XXXX XXXX XXXX SD XXXX Mailed via USPS on XXXX. 

She guaranteed she would remain with the case until resolution. However subsequent callback commitments and follow up calls she has been a complete MIA. She failed to keep any of the callback commitments, and refused to respond to several callback request XXXX messages. 

Next supervisor I dealt with has more or less resulted in the same neglect. 

XXXX XXXX, Team ID XXXX, client relations supervisor. 
XXXX instructed me to fax the W-9 submitted on XXXX to XXXX. She promised she would research the total amount illegally withheld for the 12-year duration across 3 connect accounts and the one unconnected account, and facilitate the refund of all withheld funds. 
1. XXXX XXXX : XXXX XXXX, delivered XXXX. XXXX XXXX XXXX : XXXX XXXX, successfully sent She made a commitment to provide status report on XXXX, but has failed to call and has ignored multiple internal emails and IM messages sent to her. 

My father also has an account with Citibank on which I am a POA. He was never informed of the tax withholdings. He also has a social security number, is citizen of a country with bilateral Tax Treaty agreements, and resident of a country with bilateral Tax Treaties. He does not physically reside in the US and ranks No income in the US. There is no grounds to charge this tax on any of his accounts, either. 

A formal complaint was filed to the back office in XXXX. 

For my 4 individual deposit accounts, Citibank fails to certify the W-9 form repeatedly submitted to them through various instruments and methods. They refuse to provide explanation why they will not certify the multiple W-9 forms and they refuse to provide instructions to resolve this issue. Meanwhile, it continues to charge monthly fees and refuse to refund previously charged fees. Every call made, they demand I re-submit the same W-9 that have been multiply fulfilled. The phantom back office has no direct number, extension, email, fax, social media accounts, and it is only a unilateral communication of certification confirmation. There has been no communication from this department, ever. It claims all taxes have been sent to IRS, thus refuses to refund any funds. If in fact, taxes were submitted to IRS on my behalf, there has been no confirmation or acknowledgment from IRS.

There is something prohibiting the W-9 certification and uploading the form to their system. They refuse to remedy the issue source, and instead demand I repeat the failed methods infinitely. This is the definition insanity. I am through attempting to resolve this with Citibank. Please assist in the W-9 certification and refund of illegally collected taxes. Thank you.