Wesbank ripoff

I have an with wesbank for car dodge journey 2014 and since 2014 Ive been paying them until I had financial problems then I had to pay via other company nonetheless I heard arrears, then I tried to pay but in March we had to close the office due to pandemic, I reported my situation to them then they said I can pay at list little amount, I did that but my arrears still remain mine, so towards end of last they harassed me wanted to take my car, then I had to pay all the arrears like R18K, then afterwards I paid monthly and uptodate, last month I received funny letter saying I owe collections department +-R3K, I called customer services and they said according to their system my account is uptodate, now this month they added the amount on my monthly statement and I disagree with them they cant do that as I explain my situation, please assist I cant pay this amount I DO NOT HAVE IT at all I need to pay ONLY monthly installment