non authorised data usage on my account at 3:00am

[westaway]

Hi 

I had non authorised data usage on my account at 3:00am approx 4GB .

[dust2dust]

The timestamped usage details are not accurate to the time. They are an accumulation of the previous 12 hours and reported on the usage details at random 12 hour periods of the day.
Does your phone show data usage at that time?