Cannot use new phone after blocking old one

[DaBiscuit]

Hi there. I recently lost my phone so have replaced it with the exact same phone. Staff member at the shop said I could use the same number. I have put the SIM card in the phone and it says o2 in the top left, but I cannot make calls or send and receive texts. I cannot see my phone number either where it should be in settings. o2.co.uk/swapmysim did not work and I cannot text 20220 to do it either.

Please help.

[MI5]

@DaBiscuit 

If you reported it lost or stolen to O2 they will have placed a bar on your account.

You need to contact O2 to remove it.
All numbers are in this guide Guide: Coronavirus Community Help and Support 

[gmarkj]

Did you report the phone AND the sim as lost?
If yes, then you would have had your account frozen/barred as well as the sim being barred.
You need to call customer services (you can use Skype to do so as it is an 0800 number) and ask them to unbar both.
How to use Skype (and the number to use):
https://community.o2.co.uk/t5/Off-Topic/A-Guide-To-Skype/m-p/1305104/highlight/true#M181823