They messing my credit record

I couldn't pay them anymore due to unemployment i tried explaining to them but they said they is nothing they can do i should try and pay, okay they ended up handing me over to ARA Attorneys. So I paid them all their money and finished paying last year November but to my surprise my credit score couldnt get any better, i decided to call them yesterday to check whats really happening with my account and to my surprise they say they haven't received my paid up letter ofwhich i've already send it last year November as soon as i received it from ARA Attorneys. I've send it again yesterday so I don't know if i should still wait or what!