Have you got the tracking info to show it has been accepted back @Neil06 ?
It can take a while for o2's system to catch up with the return - unfortunately you will have to keep pestering customer services.
You can call 202 or 0344 809 0202 (assuming it was a contract), OR 4445 or 0344 809 222 (PAYG).
Best time to call is 8am.
Or you can message O2 on Facebook ( https://o2uk.co/O2CFB) , Twitter ( https://o2uk.co/O2CTW) or Instagram ( https://o2uk.co/O2CIG).
Please note, this is not customer services and we cannot access your account. Do not publish personal details (email, phone number, bank account).
Link to our guide on how to contact them can be found here
