You need to contact O2.
All numbers are in this guide Guide: Coronavirus Community Help and Support
You can also try saying "Upgrade" or "Fraud" to be connected to an advisor.
Hi @BronaghWylie1 , welcome to our community, and sorry to hear you're having some confusion with your billing after cancellation. I hope you manage to get everything sorted finally with customer service as advised above. It would be great to hear how you're getting on with this.