Data used up

[Timisfrustrated]

For the first time ever I have had a message to say that my data allowance has been used up - but I have not used my phone differently in the past month.  What has changed?

Can anyone advise me - since it seems impossible to find a way of speaking to a human being and "Aura" is incapable of responding to my question?

Thanks in advance!

[MI5 · Accepted solution]

@Timisfrustrated 

You can check on your phone which apps have used data and how much.

If your phone doesn't agree with your MyO2 http://www.o2.co.uk/myo2 you'll need to call customer service.
Numbers here Guide: Coronavirus Community Help and Support 
When it comes to the reason you are calling stay silent for 15 seconds and you will be taken to the keypad options.
Press 2 for Everything Else
Press 5 for More Options
Press 7 for Anything Else which will put you though to someone.
Say "Upgrade", "Lost/Stolen" or "Fraud" if you have to, to get put through to someone.
8.00am is the best time to call if you can.