empty promises

I was helping a friend looking for a car when I spotted a car at primo executive cars in boksburg I contacted the salesman bright and arranged the deal and the deal went through, when we went to get the car bright told me I would get a commission for spotting the car and the deal being successful and that was on the 18 of February and he said I would get the money the next day but to date I have not received it and he has just taken me from pillar to post. I tried to contact the manager Rudi and he promised to sort it out but turns out it was just another empty promise. I didn't ask for commission but they promised wonder why promise if they can't keep it.