Closed contract on default

I had a contract with cell c which I paid and settled in December 2019, I called soon after to ask for my contract to be canceled and I was advised that it was canceled. I have taken two separate contracts after that but on my credit bureau Ithe 2019 contract is listed as a default.

I have been emailing proof of payment non stop asking that the default be removed as it is messing up with my credit profile. I decided to pay again the outstanding balance that shows on my credit profile. This is after I have called multiple times to check if this account was active and in all those times I have been advised that the account had been successfully closed.

I have been emailing once more the proof of payment and no one is willing to help.