I've gone back over months of bills and my usage seems to be much the same each time until Nov, I can't see any thing unusual until the 29th.
How much data is included in your tariff?
Only around 2gb but I've never used much so I've never needed more.
Do you know how much was used?
In September I used 1.87mb, Oct 317mb despite having my mobile data switched on, then in Nov all of it within around 2 hours.
Right I see. What I will do is private message you to get some details so I can take a look at the account.