Increase

I bought a car through mfc and started off with a payment of around R3800 in January last year. The instalment increased twice last year and it seems like it's increasing every second month now. I am now approaching R4000 installment which I haven't planned for. I just wonder how much will I end up paying if it goes on like this. No1 ever told me the installment will increase hundred times a year. Unacceptable if any1 thinks of buying a car rather get finance everywhere else except mfc