account in arrears

i had an account with mtn, this year i managed to settle the account which was handed over to SSDA now that i want my paid up letter i am told by mtn that am still owning R8000 while SSDA collected in full the amount owning and i tries reaching to mtn customer but no one is helping me and it hurts me because i have paid in full and i just wanna clear my name so i can buy a house for family, is this the treatment you giving your clients, i have sent email to them to please send me a statement of the account to see how it possible am still owning and it been 3 working days now.