on 17-07-2020 14:40
on 17-07-2020 15:11
on 17-07-2020 15:11
on 17-07-2020 16:35
17-07-2020 16:55 - edited 17-07-2020 16:55
17-07-2020 16:55 - edited 17-07-2020 16:55
Usually due to a network fault or maintenance.
Check your postcode here O2 Service Status
Rebooting your phone can also fix it.