FNB stopping me from getting loans with other banks.

I have a Covid loan with FNB that I fell behind on. I have been making payments since Febuary this year when my financial situation improved and assumed that since I started paying the loan everything is ok. Much to my surprise when I tried to buy a new car now I was told I am listed with ITC and not making any payments on a loan. When I contacted the Credit Bureaus I found out that FNB have not been updating my payments. After numerous emails to there care email where they didnt respond I phoned them and was told FNB wont update my payments unless the whole amount is settled. I was then told I wont get any credit anywhere for anything untill the debt is settled. But the same FNB gave me a loan of R200k -4 months ago to pay a SARS debt. This loan was given after I was handed over to laywers. So FNB is willing to give me a loan but is stopping me from getting a loan anywhere else. I was even told last month that I qualify for another in December.

I understand I am behind in this debt but I am paying what is due every month and am not behind in any aother debt. They are effectively stopping all other banks from dealing with me so only they can lend me money.

I cannot see how that can be legal or ethical. Has any else had a similar experience? Is this just the way the law works?