Unhappy Client

I registered with Intec College 2019 got the portal access for one month and after that I could not log in anymore. I tried to call them and sent e.mails but they said I owe them. My course was R17000.00 and I paid them monthly a some of R10 000.00, still owe R7000.00.and they keep on sending invoices and now they have listed me because I said I will not pay them until they give me proper service. I do not know where to report them or clear my name. They never gave me a chance to submit even one assignment. The only thing I did with them was to register