Deactivate your data service on your phone if you don't wish to use the data service. +1
dont la later complain pula [why SH didnt preactivate this service] [i have to activate from my end/call 1633? its so inconvenience!]
I think the lesson learnt here is: It is important to check the bill every month. It does not take more than 5 mins to look through the bill. It is good to log any dispute at the earliest moment.