on 02-09-2024 11:25
on 02-09-2024 11:32
on 02-09-2024 11:37
As you are on PAYG?
https://community.o2.co.uk/t5/Pay-As-You-Go/unreadable-title/td-p/1744289
You just stop using your sim and it cancels automatically after 6 months of no use.
If however you were forced into a contract, as mentioned in your other post, you need to cancel under the change of mind period.
https://www.o2.co.uk/help/device-and-sim-support/returning-your-device
Guide: How to find help & contact O2