ATT New Line Deposit Refund

Post Paid Account. 

I am trying to get some help with my refund issue since the customer care number seem to be either screwed up or ATT rep's dont want to help me. 

Issue : A few weeks ago, i have added two new lines and had to cancel them in a week. ATT charged me taxes and a deposit of $300 ($150/per line). Refund on my taxes were completed but the deposit was never returned to me. 

I have been calling ATT every day for the past 3 days and I can't do this anymore. Everytime , they say they are going to connect me to billing department and thats it... long waits, disconnects, and sometimes ending with a wierd message "your call cannot be completed at this time. Call again later". This happened 4 times in the past 2 hrs. This is just so frustrating. Each time i call ATT , i try to explain the rep the situation and they need the enitre details of the account - first name, last name, phone number ... only to say they will need this information to pass on to billing department. 

ATT doesnt seem to be employing any BILLING SUPPORT. This, to me , is a fraud.. by not supporting billing related issue and extremely poor customer support. I have 8 lines and will be seriously considering to switch to another provider. (I ll just say it... VERIZON).