Very rude official

I wish I can give them no star. I am sooo disappointed with SASSA. Previously I received excellent and very courteous service from all the personnel in Pretoria. Yesterday, unfortunately all that changed when I was treated very rudely. The official manning the queue was very rude. I asked him nicely, sir can I please ask you a question, he turned his back on me and when I repeated my question he said he is not speaking to me, when I said I just want to ask him a question he turned on me and asked me if this is a race thing, do I expect to get preference to all the people in the queue, waiting. I said no, I will take may place, I just want to ask him a question to make sure they can actually help me. I am 69 years old, have bad knees, needing a knee replacement and standing for a long time is very painful, I just wanted to make sure I will not be queuing if they cannot help me. Where did this "race" thing come from? I spoke very nicely and had no intention of jumping the queue, I just wanted to ask him a courteous question before I take my place. I think it is very rude to turn your back on someone asking you a question and then turning on them with the race card without any reason.