Mobile phone gobbling data

my mobile phone is gobbling data.

my sim only contract has 2 giggly bites of data which has always been more than enough to check facebook every day if I wish to. in recent months the data usage warning has been popping up earlier and earlier and this month after only a week.

I have done a virus scan on avast and it showed no threats.

the data appears to be mostly used on facebook. I have been getting ads running in the middle of facebook videos.

I have tried removing apps like trip advisor which I dont use.

peel remote and something else have been driving me mad with lots of ads popping up so I tried removing that and got a warning about losing data so I didnt do it.

any help appreciated.

When you are at home, I presume that you are using phone over the Wi-Fi. Double check if phone is properly connected via Wi-Fi, not via 4g/ mobile data. Are you watching lots of videos? Because, video streaming is major data consumer.

Check it's not got a wifi booster setting or something similar, thats when the wifi signal isn't very strong so the phone switches to using mobile data instead.

Can rattle through your mobile data at quite a rate and not even realise.

Videos will eat a lot of data, you can stop facebook videos from auto playing when on Mobile Data, that may help...