Repossessed my car and need it as i a Rep

I changed jobs last year and had a salary cut on top of that I had take care of my son alone as the father disappeared. I got my pension fund and I was ****med of 59k, I opened the case at Edenvale police station and it was thrown out, I was in arrears for 5 months they repossed my car and I made arrangement and I paid R30k they gave me the car and I had arrears od 6000k, they asked me to pay extra and I couldn't I paid 4k instead of my normal instalment of R4400k. I skipped December 2014 because I had to put my son at school and I used my car payment money. BMW immediately got a court order and took my car and they said I must pay R12800 by the 6th of Feb, they then send me and email on the 3rd saying I must settle the car or else they have a right to sell it. I am rep by profession, I stay at Boksburg and my son schools at Edenvale. I told them that I have stopped all my accounts just so I can pay rent, insurance, food, my school and the car. I need the car and cant afford to be backlisted. I at the brink of loosing my job because they hired me with a car as a requirement, I have been their client and they saw I was struggling last year and now they treat me bad, PLEASE HELP ME