Confused Still

When I switched from Verizon I was not under contract, only owed on 2 phones. Someone please tell me how receiving $153 Visa card is all I get from Att for the 2 phones I gave them. Will I also be receiving more as a credit on my bill each month for the remaining cost I owed on the phones? My bill is showing $20 credit on each phone monthly. Is that it? I'm trying to find something to keep me from ditching ATT the first chance I get.