Dmc awful service

I made an agreement to free this account and dis my last 1600 on 27 December but get a message saying i dishonored my agreement and they refer to me as sharon mosesy old surname, called them Lady nt competent, said i dnt owe anything then asks when i paid said sorry they made a mistake or u gave wrong name. How *********** is that, they need ro give me a paid off letter n urgently update all credit bureaus, they promise and say they helping bt soon as money is received no more care about customer, thier watsup service never ever answered, terrible service