my experience with postpaid well different
when i had a postpaid account it was from lime and it was a superpack for 2K.. also got BIS dataplan for the grand total of 3.6K a month..
had some problems, soemone stole my phone and i told them to deactivate it - however the DIDNT deactivate it and the charges rolled over.. so i saw a bill of 8K including tax.. told them i was not paying that and that i already reported my phone stolen and they put my claim on query and revoked the extra.. so i decided take off the BIS and throw on a 500MB 3G dataplan for my SGSII - in the middle of the following month my phone gets barred for non payment so i decided ask them about it so they told me that i have not settled an outstanding 4K - i cussed and gwaan bad and told them that it was under query and they revoked my bar.. now when that month ended and i saw my bill, a whopping 9K was on my bill!! was so furious i called and asked them what it was about - apparently the outstanding 4K was still there as well as the next month's payments and the extra was over-rolled minutes (which was funny cuz half way into the month my phone was BARRED)
so i payed them 8K just to get them off my back that month end.. now in the middle of the next month - they barred my number AGAIN claiming i had an outstanding bill of 3.6K, i told them i only owed about 1000 and told them my bill number but they brought up that the query was settled and stated i still owed them extra.. i told them i was not paying cuz for that month my phone was stolen and i reported it - they said i should still pay and if i dont pay this month the charges will roll over to next month.. so now my phone has been barred for bout 2 months with over 15K in roll over charges
long and short of it - id much rather buy 3.6K worth of credit for the month (which lasts me the whole month and longer) and get both data and calling without any beef rather than deal with that ISH again!!