You don’t want to get charged for the services that you accidentally activated. Or maybe the kids in the house subscribed to some unwanted services. Kids are smarter than their parents these days with technologies. So maybe you are refilling your phone but something sucking all your money in. There could be 2 reason that I can think of. Your data pack is not active and you are browsing the internet directly which will drain all of your balance fast or some Value added services are active. You can easily stop them by dialing
*121*6*1# (free) -> This will stop all VAS services except welcome Tune, Call Block Services, Music Radio & GP Music.
If anything confuses you just go to their website https://www.grameenphone.com/ and click on the bottom right corner to chat with a customer care and they will help you out with the proceedings.