Over charging and unprofessional service

We went to Hillfox McDonald's on Thursday 12 July 2018 around 12:00. After standing in the drive through, waiting for 5 minutes for the waitress to get the order right from the person in front of is, we eventually got service. We ordered 2 medium Grand Mac meals, with Cokes. Advertised on their boards, the meal cost R59.90 each We ordered and was told that the total amount was R140 odd. Quite confused, we repeated that it was the Gran Mac Medium meal, the assistant said yes, but the special is only with Coke. We repeated that yes, with Coke. I said to hubby it's not worth R40 more, but being lunch time, he was hungry and paid the R40. We got home and I wanted to see what we where charged for, only to discover that we never got an invoice or receipt. All and all, I would not recommend that McDonald's to anyone. When I told my mom about our bad experience, she said that they had a similar experience there, that's why they usually drive to the McDonald's on Ontdekkers.