my SIM card has been deactivated by O2

[Dabas]

I have a pay as you go mobile phone which I use for emergencies. It is always in credit and has served me well for many years. Recently it has been deactivated by O2 without prior notice to me. I can find no advice as to how to reverse this and get the phone working again. Help is needed. Barbara Mayfield.

[pgn]

Ah yes - you will need to talk to O2 to get it reactivated: Guide: How to find help & contact O2 

The PAYG account needs to make one chargeable call in a 6 month period so O2 don't deactivate it, especially if it is one of the legacy PAYG tariffs (eg Classic).

Good luck - if you use Social Media, either of the private or direct message ways in the guide shared above will get you through, with a bit of nudging, to someone on the UK Social Media team for O2 who can help. Your balance needs to be reinstated too. Good luck @Dabas.