worst collection consultant and bank ever

I have the worst financing ever. I bought a car with MFC and I agree that since the first day of my account it has never been up to date till now, at least I believed so. I have bought a car for business and it hasn't been going well and always I would call and let them know my problem. I even requested for them to cancel my debit order because I did not have a stable date for receiving money. I have even asked them to give me a payment date of the 7th of each month. I received a call from a certain guy saying he was instructed to come reposes my car and that time I had planned to pay all my arrears. I told the guy he should not because I will pay by the following Monday. and yes I paid most of it and was only short r34. on the 2nd of October I made sure I pay R5300 which according to me it was gonna cover the R34 as well as my installment is R5256.66. to my surprise I received messages to contact *****gwa from MFC because my account is in arrears by r503.74. I tried to call her and her manager Eunice but till now no answer. I even sent *****gwa an email asking her about the amount but till now she hasn't gotten back to me. the service I receive from the so called *****gwa is the worst. she's never available to listen to clients queries but she's very good to tell us we haven't paid and instruct people to reposes. I even called the call center and they transferred me to her and still no answer. the only time she listens is if you request for a settlement or if she's on lunch, someone will tell you she's unavailable. her service is the worst ever. I need answers, I need to know where the R503 comes from because even about 2weeks back I called the bank letting them we on strike and need to make a payment arrangement but I was told my account is still new and the guy even confirmed I'm in arrears by R34 but today its a different story, he told me its either I pay or sell the car. what kind of disrespect is that? my fellow colleagues where assisted by their banks but MFC told me my account is still new that time its 10months now , I did not fight them instead I paid. I'm disappointed by the kind of treatment I get regarding this account.