When you are getting a huge increase in data use, for no reason, it may be a device problem.
Sounds like you have an iPhone. Start by doing a hard reboot. Hold power and home button until your device cycles off then back on.
If this doesn't stop data drain, backup and factory reset. Contact Apple if you feel you need more device support.
Sounds like you have an iPhone. Start by doing a hard reboot. Hold power and home button until your device cycles off then back on.
If this doesn't stop data drain, backup and factory reset. Contact Apple if you feel you need more device support.