unfairly blacklisted

I was employed by Sanlam as a financial adviser in May 2018 where i was paid a basic salary for the first two months only and there after it was commission only. when you start they give you a compulsory technology loan to buy a laptop and other devices you will need to do their job. I worked there for 10 month without any income, I was spending a lot of money on Fuel and servicing my car go to see clients ,money that I did not have . That is when i decided to resign in February 2019, because it was more of an expense to me than a job. Just after a month of resigning I got a call from their rude debt collector (Diane Karim) from DebtCor saying that I had to pay back all the salary and the technology loan I was granted.and at that time i was still unemployed, I informed her that i was in no position to make any payment arrangements as i had no income and would revert back to them for an arrangement once I have an income to back my promises. She kept calling and harassing me for three consecutive days. then she sent me a threatening email that she would blacklist me. which she really did soon after that. so now my name has a judgement on which i feel is unfair. i was never given any opportunity to settle and find a job first to pay them back, another thing is i do not mind paying back their technology loan but a salary which they paid me for two months does not really make sense it was not a loan. i want the judgement removed from my name then i can make a payment arrangement with them.