Incorrect listing

I have an outstanding debt which was sold by African bank to nimble of about 38k I have made an arrangement to pay 630 a month but Nimble won't update this on the credit bureaus. They have made my credit record seem like I pay 38000 a month not 630. When I asked them why, tell me it the bureau that is how it done. I will have to settle the entire debt for it to removed. I earn about 17000 a month, how do I have a instalment of 38k than they **** and say the bureau sent the information not them and the bureau did cause they don't want me to take anymore debt. I want my instalment to be updated correctly to 630, what they doing is ******* and I am taking legal actions against this