on 26-06-2020 11:30
on 26-06-2020 11:35
You may be restricted if you have been abroad for more than 63 days without returning to UK.
If not, try manually selecting a different network or just simply rebooting the phone can help too.
on 29-06-2020 11:48
on 03-07-2020 18:31
on 03-07-2020 18:44
on 03-07-2020 18:44
How long have you been out of the UK?
Have you checked your MyO2 to see if you have any data left http://www.o2.co.uk/myo2 ?