My complaint is with XXXX XXXX service. I was under contract with them to pay {$120.00} per month for bundled service ( TV, internet, phone ) through XXXX/XXXX/15. This past XXXX, XXXX changed their billing system and, because of a " glitch '' in the new system, I began to be charged {$210.00} per month. I have made repeated attempts to resolve this issue by phone ( over XXXX hours on the phone ) and in person but have not been able to get it resolved. I grew so frustrated that I cancelled the service and tried to calculate what I thought I should pay. I forgot that the monthly bill is paid in advance so I actually have overpaid XXXX by more than {$100.00}. However, because of the billing system problem, XXXX continues to send me a bill for {$25.00} and just sent this amount to a collection agency. I have continued to call XXXX to resolve this issue ( ticket # is XXXX ) and been told several times that a supervisor will fix the issue and/or call me but none of their promises have been kept. Meanwhile, my credit will be affected by this since the bill is now in collection.