Extortionate data bill

[KevinM]

Just received a bill of £1500 this month for extra 50gb data used. I have never gone over my 30gb of data (charged at £30) in all the years I’ve had it. It’s a complete shock to me. O2 admitted there was a problem on my phone data for that month and credited me but will not credit any of the £1500 ‘used’ on a different sim. I do not know how this has happened and O2 are not willing to help. Please can someone advise.

[Bambino]

@KevinM If O2 won't help, try Resolver: https://www.resolver.co.uk/companies/o2-complaints?territory_id=5

Other ways to lodge a complaint can be found here: https://www.o2.co.uk/how-to-complain