Very Frustrated and Annoyed with DMC

I have dealt with DMC to settle my accounts I had with Finchoice, I paid up after trying to negotiate discounts on this accounts which I didn't get, However I settled all this accounts then I had to make follow ups with my Paid Up letter, out of the 3 accounts I settled I got 2 paid up letters after 3 months now we almost at the end of the year I haven't received the last paid up letter. I've sent mails and made calls no one has assisted me till this day.