Questionable service and attitude from a staff member

Last night on the 20th of April , we visited Burger King in Plumstead ,Cape Town. We pulled up and were greeted warmly by a very friendly security guard. My partner remained in the car and me and my son went in only to be told they were only doing drive tru orders even though the doors were wide open. I left but the security guard stopped me and said that it was open and took me.back in. I showed him the cashier who told me and he spoke to her in their mother language. She apologised feebly and said she looked at the time wrong. I was served by another employee.The thing that came to me afterward was that some of the other staff on duty heard her tell me they are only doing drive tru and saw me leave the restaurant but no one said anything. While I was waiting on my order their was more than 10 people coming in after me so I am left to wonder was it because if they were prejudiced even though I was dressed very neatly albeit it was in a islamic wear or should i give them the benefit of the doubt and assume they already cleaned therefore wanted no customers in store which is an unprofessional attitude toward customers especial loyal ones like us as our Autistic son only eats Burger King take away food. Unfortunately the one we frequent in Kenilworth Centre is closed for renovation. We are such regulars that when they see us coming to buy some of the staff members will shout our order to the kitchen before I am even by the till in order for my son to get his food asap. We even hug occasionally if we bump into each other outside their workplace and i buy some of them chocolates now and then as i really appreciate when people go out of their way to proviide a good service especially as working with people in such an industry us not easy at times.