AT&T Aka Bellsouth - Cingular Did not refund deposit billed to my credit card via online order. Internet

Its is exactly 28 days after ordering internet services via online application on AT&T's website, a charge of $50 for a deposit was done immediately on my Visa Card. I cancelled 10 days later after going through several different people/departments at AT&T to understand that my deposit (done by Visa Card) was not enough (there was a previous bill not paid under Bellsouth) thus I cancelled the service stating that your online applications said nothing of previous bills or the possibility of owing more. After talking to several more people/departments I was told my deposit of $50 would be refunded in 7-10 days back to my Visa Card.  Another 12 days later I have still not received a refund to my Visa Card and upon calling AT&T again, I was told (after talking to 6 different people/departments) that a form had to be filled out to Accounts Receivable and a check would be mailed out in 2-3 weeks.  According to this last customer service representative, "a deposit usually goes towards any unpaid bills upon cancellation". I was never told that when I cancelled back 12 days ago - I was told I would receive a refund as it was taken as a deposit.   AT&T was a good company until they got too big for their britches and bought out Cingular and Bellsouth.  Now they just bite and so did Bellsouth!  I thought we were past all these big companies owning more than they should. Where is AT&T/Bellsouth's competition?