Cashback

I bought a car last year with sa cars solutions and we sign a contract that I will get R12000 cash back which will be paid on a monthly basis for 12motnths, they did pay R1000 from august last year till December and then things turn around in January where I didn't get it and I have been calling them since mid January they even send me to big boss and he kept promising me till today. and now they have to pay for January and February and on Wednesday he promised to pay it by Thursday and today is Friday nothing.