Denied settlement letter

My account was handed over to Nimble by african bank they have been nagging me for payment until I managed to get some cash to settle. I was giving a settlement amount of 29k and promised a settlement letter within 7 days. I have made the payment its 30 days now i struggling to get the settlement letter and whats worse no one is able to assist my credit profile still not updated as promised its a very dishonest company. can they just send me the settlement letter i will be out of their face