Poor service from VODACOM

I have been trying to call Vodacom cancellations department with no luck. I paid off my vodacom account in 2018, send proof af payment to the cancellations department, even today I have not received a response from them, I have not received a settlement letter. When I try to call the cancellations department, they say they cannot help me as my number is now a prepaid number. When I called the accounts department, Dimpho and Karabo claimed to put me through to the cancellations department only for my call to be dropped after. Please assit me, as this is affecting my life.