Text messages about bill

[Deedoll61]

I had 2 o2 devices, but last year one was changed to another provider. Every month since the change, that phone gets a text message to say their 'bill' is ready to be viewed.  But there is no bill.  The phone has a new sim and no charges are being made on the remaining o2 monthly bill.  It's just these text messages that arrive every month!

[MI5 · Accepted solution]

@Deedoll61 

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.