Mtn contract

I had a contract with mtn and it was in 4months arrears, I settled and canceled the contract in September this year. Now I am applying for vehicle finance and I am being told that I have an mtn account which is in arrears and it is blocking me to get vehicle finance. I sent emails to mtn even went to the shop at savanna mall to request the cancelation and paid up letter but I'm not getting any response. I need the letter as in yesterday because it is blocking my way of getting finance yet I settled the contact 2months back