Damelin must do their work efficiently and deliver quality service! Stop threatening me!

I registered with Damelin in 2018, January I got sick and was admitted in hospital. Due to health problems and finances I cancelled my registration at Damelin. Mthokozisi told me that it is cancelled and must rest assured that my account will not be debited or charged as I cancelled. I did on the phone and in writing. I started getting smses that I owe Damelin, when I phoned to enquire I was told Mthokozisi is on leave and I must speak to accounts department. I spoke to a number of people at Damelin, most of the time when I call I am told the people are on leave or no longer work there. I was told it takes long to credit an account, in the meantime I am getting threatening sms and they even had the gall to call my sister and say I owe R30000. I never received anything from them e.g. student number, books etc. nothing and never attended any classes. I submitted all the proof they required they lost them or misplaced them. Then submitted again, I am being threatened to be taken to credit bureau. This is so frustrating, how can an account that was cancelled in January and had to email again in March 2018; still be open even after a year. Sinethemba said it takes long for an account to be credited but really, more than a year? They must hire people who are efficient and competent in their work and do their work. It was not my fault that the first person did not do his work before leaving the company. Damelin must do their job right.