Threatening to repossessed the car

I bought a car in 2014 and it was a contract of 72months now I am left with 5 months to pay the car, I was retrenched in 2018 but managed to keep the account up to date till early this year in January when I phoned to request holiday pay and was told to pay 50%because of my installment been too high R 10500.00 per month and I did that at the end of January I paid R 5000, and on the first week of of Feb I received a call that I am behind I told them that I made an arrangement to pay 50% and information was found I forced to pay R15000 end of Feb and I have only 5 months to pay off the car and arrange to pay off the balloon now they threatened to repossessed the car