$500 Deposit? Really unsatisfied with aT&T

Okay Ive been with AT&T's darn expensive phone service since 12/13/12 and didnt require a deposit when I first signed on or got the contract. Its been almost a whole year of commitment to this At&t rip off services and then I skip 2 payments and when I called yesterday to pay my past due bill now they're asking me to put a $500 deposit which will be refunded at the end of my contract...They said my services were cancelled due to not reaching payment agreements and they needed to reinstate my phone service which then ran a credit check  but what about all them other months I've been paying my bills on time if they take the time to look at that....a year to late for this ridiculous amount if I had known sooner I would never give att my time & money...its no wonder why people with att always complained about their service and I wish I opted out sooner....

Also I asked the representative which handled my bill over the phone if I could just pay this months bill along with my termination fee of $225 to avoid this ridiculous amount of deposit and she stated yes sure but you'll need to pay it before your due date to avoid that charge and then goes on to say I will bill the $500 deposit amount on your next bill but make sure you pay your bill and termination before its due date okay! OOuucChh UUmmm was that just a big slap in my face or what?

To make matters worse I later spoke with the collections dept. and the representative there said no sir regardless if you payed your next bill and termination fee we will still need the $500 deposit after the cancelation on your account and you will be refunded because It had already been applied to your accounts next bill....can somebody tell me Im not the only one that think this is absurd im cancelling my service and paying my bill & termination fee but you still need that depoist...Refunded or not that is not my point At&t clearly dont care for their customers AT this point im infuriated with At&t and I wish this on nobody but beware at&t customers of the sly and selfish ways this company sucks in customers and spit you on the ground somehwere down the line....

open for any advice, comments, tips and answers!! Thanks for your time