Multichoive ****

I bought a decoder early this year, and I paid for 3 months then stopped since it's a prepared, no they say have my details on credit berua saying I owe them R1856, well I tried reaching out to them and the agent who was helping me asked me if I once took a contract decoder with then I said no, then said my account it's under investigation, asked her why, she couldn't give me an answer then I asked her to send me the contract agreement and she said she can't do anything, now this thing it's affecting my credit score badly