GymX Fitness Do not sign a membership with this GYM! They do not abide by the terms of their own contract. Waco, Texas

I purchased a 1 year membership at GymX Waco, TX for my then 18 year old son.  I made the purchase online so I filled out his name as the member, but attached mine as emergency contact and also used my credit card to pay for the intial down payment and then each subsequent monthly fee.  The one-year commitment expired on 9/9/11.  My son wrote a letter requesting to terminate, as the contract instructed, signed it and mailed it on 8/1/11 to the address the contract indicated.  A few days later the letter is returned to us by USPS citing "Forwarding Order Expired".   On behalf of my son, I scanned the letter, the original contract and a copy of the envelope showing both the postmark date and the return reason and emailed this to GymX ( an email address on their website) with a brief explanation of what had happened etc.  I explained I was emailing on behalf of my son because he no longer lives in Waco, but has moved away.
I knew to expect a debit in September, that was the last payment.  But then I was debited in October.  I tried to call the Waco number several times and the results were: no answer, answers in Killeen but she can't help me, and I need to call ABC Financial (their billing company).
I called ABC Financial and they can't help me.  I filed a complaint with the Better Business Bureau, even they could not make contact with the Gym owners.
I scanned a copy of the contract, the letter requesting termination, the original envelope that was returned by USPS, a copy of the email delivery confirmation and sent it to ABC - tyring to get them to stop debiting card.  They passed on all this information to GYMX owners and confirmed this in writing.
BBB closes my case as UNRESOLVED, because they cooperation.
I continued call occasionally - never getting a response.  I also emailed and never got response....and this is me PLEADING for them to please just take care of this.
Along the way, I stopped payment with my bank on the debits from ABC Financial/GymX.  I was billed for October and November and it was obvious this was going to continue.  I/My son gets a bill each month telling me my card has been declined and that I now owe late fees. Each month, I sign it (my son signs it) and summarizes the dispute and sends it back.  Again no comment from either ABC or GymX.

Finally, concerned they are going to try collecting on the past due amounts -- I copied all documents, all attempts to contact them and sent them via UPS overnight letter delivery -- so now I have a signature and PROOF they have received this request to terminate.

How do I make this stop?  I have gone to the Gym asking to talk to the owners or whomever before, but "they are not here now".  Honestly, at this point in time, I am so stinking mad I can't go to this place and behave appropriately to people that are obviously crooks.  So I won't.   Do Not Sign a membership.   Find another gym.