they refused to let me cancel my registration.

in 2014 I registered with Intec 3months later I decided I actually didn't want to study with them , and due to financial constraints, I requested a cancellation and was told that I would have to choose another course instead but cannot cancel . I advised them of this even when I was made to rather change a course, they then changed it, (blacklisyed me still for a course I had cancelled) then my financial problems that I had then when I wanted to cancel haven't changed till now, I get calls to make payments , that I know I wont afford and get threatened with lawyers, I don't remember getting not one single call asking me why I haven't submitted my assignments , when am I going to write my exams !!! all I get is calls demanding money that I had initially told I don't have but was rather made to choose another course, now I being blacklisted for a service they never really provided. Its a sad day in south Africa when people want to take your pennies for a service they know very well they didn't provide, my credit record is already messed up due to them saying I owe them for two course!!!