Standard bank Account not being updated

I payed my standard bank cheque account in September last year through Nimblegroup,But my account was never updated and Standard bank has even handed me to other attorneys now.I have called Niblegroup for a payed up letter numerous times but no results...Its been almost a year they can't update my status on this account and these attorneys are threatening to list my name on the credit bureau for money I payed to nimblegroup