Account not updated on my credit score

Hi jet store sent my account to vvm group for collection I then paid my jet account on the 1st of September 2020 R8450 as a final payment I even sent them my proof of payment they confirmed that they got it, but they haven't sent my paid in full letter, and now when I contact them they don't even reply, on the 9th of October received an email from jet saying sold my account to nimble group I mean I paid like a month back shouldn't my account be updated why would jet and vvm do this to me