Bad service recieved from Midas - R55 (Monavani)

Went to Midas Circle Center to buy wipers, as I got out of my car a guy approach me and asked if I was there to buy, wipers/lights and I said wipers and he said he will help me with removing my old wipers as they will require samples inside. I refused as He did not wear anything showing that he was working there. When I went in the guy who was assisting me asked where my car was and i pointed at it and he said he can not go out side so i need to bring in the wipers samples and he then called the same guy i refused to be helped by. Th guy started blaming me for not agreeing to be assisted by him at first. I questioned both of them on how am i supposed to allow someone i don't know who is not wearing uniform to help me. I thought that if i give them the car information they will pick the size from it while i am inside. The guy then gave us wrong size wipers to fit, after we returned them back again in store. he gave us another size, which was better. The one guy i found outside requested that i give him money for helping me. i have him R15 and said thank you. He then demanded that I give him R50 for helping me as he doesn't work for free and he needs to give the security guy and the one guy who sold the wipes a share of the money. i refused and drove away