UN HAPPY CUSTOMER

I'm honestly not happy with this company. I had an account with home choice in October I requested for a settlement letter which I received, and the payment was made wright on time I then requested for a paid-up letter till today I still have not received it the worst scenario I am busy receiving emails telling me with the interested which are a pilling up and I cannot afford to pay those interest. I still need my paid-up letter because the payment was made intime they will have to override those interest fees I'm trying to fix my credit profile then how am I going to do that if it is till reflect as unpaid, please I need this to be rectified ASAP.