Creditor Refusing To Update Credit Bureau

I closed/ paid-up my Nimble Account on the 31 October 2023 and Nimble still hasn't sent an instruction to TransUnion to close the account - see attached communication with Transunion.

When I call Nimble they are now talking about the fact that I have to wait 21 working days for the account to be updated, 21 working days have long passed and my credit record is suffering because of this as the account on TransUnion is still showing the balance I paid almost 2 months ago.

Spoke to a Mikayla and a Chantal from Nimble and they both said, they sent TransUnion an enquiry about the status of closure for this account and they haven't received a response.

But when I asked them for the File number of the instruction sent, as requested by TransUnion (as per attached screenshots), they could not provide it. They are now talking about 21 working days for the update to take place.

I cannot log a dispute with TransUnion because 60 days still haven't passed yet.

Please advise, what should I do in this instance.