locked a old contract phone

I trust you are well.

I would like to raise a concern regarding two contracts I previously had with your company.

One of the contracts has been fully paid and was completed last year. However, I have noticed that the device linked to this contract has been locked/blacklisted.

Please note that this contract has been settled in full, and I kindly request that the device be unlocked immediately, as there should be no restriction on a fully paid and completed account.

I do understand that my current contract is in arrears, and I am willing to discuss arrangements regarding this. However, this should not affect the device linked to a separate, fully paid contract.

Please could you urgently investigate and resolve this matter.