Bad Attitude/Billing/Derogatory ***ist, racial

I went to the Shell at VanRiebeeck Park next to the KFC with my 8 yr son for R100gas, after I left the light did not go off nor did the guage go up-new car, I went back& asked for the guy who helped me, as soon as I told him what happened he went to get the slip, but I explained and asked if there is a problem with the pump, as the guage is where it was when I came in,he then said in zulu that I should complain to the mlungu and I said fine. The manager came over and asked what happened as I am explaining to him Kanyo kept on interupting and was being rude, the man then said that he must put the R100, but Kanyo the refused-which is a sign of insubordination in front of a customer, I even called him to check the guage himself then he started verbally abusing me in front of my son saying I must voetsek and I retaliated as well. I told his manager that his service ***n sucks and Kanyo said in zulu nina abantu bam nyama nithanda izinto ze mahala which I found offnsive because I had paid, he then said ngi voetseke nobubi bam and I retaliated and told him that his granny is ugly he continued hurling insults&refused2giveme the slip&said he will use it 4 zol. This was humiliating&unaccept