This is for your info only.
I have been using my M1 line for many years without knowing that GPRS and Video calls are activated even though I did not request for them.
Both services are charged based on the data volume transmitted. My current bill has a $100+ data charge, and I don't even know when it was incurred.
I have called up M1 to terminate both the GPRS and Video call services so that there will not be any future "accidental" data usage.
You may want to do the same too.