Bad service and backwash in drinks

I have been to McDonalds on Sunday afternoon to buy food for my family. First of all it wasn't busy there were like 4-5 cars in front of us at the drive thru. We waited between 30 - 45 min from start to order to the delivery. The order wasn't correct. The junior burgers in the shared box had no sauce on them. the chips was cold and the milkshake was like mixed chocolate and strawberry. I phone the customer service and lay a complaint about it. Later during the day Mpho from that branch phoned me and told me that he is really sorry about the service I must come around and ask for him he will replace the order. I went there last night, Mpho wasn't there. the lady in charge there was treating me like an animal when I told her Mpho said I must ask for him by name. I explained to her the situation on Sunday, her attitude was like you are complaining because you got to much money. She only replace the shakes after telling her staff to backwash in it. the staff thought this was a huge joke. I'm going to take this up with the local news paper and health and safety. I would also like to communicate with the store owner. I also have a witness it all and didn't even place an order after all.