Don't ever make a mistake of going to DCC

I registered in February 2019 for a course in DCC, paid R3400 for registration but I cancelled within the 30 day period. They still haven't gave my refund back and they have listed me on the credit bureau, also they keep on deducting R1400 via debit order which I keep reversing because of them. I'm tired of DCC, and they should just refund people and close down cause it shows that they don't know they work.