help with at&t pay as you go plan

[aizel_babe]

question: because i bought an iphone from my friend and it is locked to at&t and accidentally i update it to ios 5.01-4.12.01 which is there are no solution to unlocked it so i decided that i will need to get an at&t sim and prepaid one which is pay as you go plans but i havent got it yet . but im browsing some forums that if get a paygo sim from at&t and subscribe to $50 per month with unlimited text calls and data. but for iphone 4 the data plans does not work. so can u please help me thanks