Long waiting time for orders, yet the store is not busy.

Greetings, This is for BurgerKing, Meyersdal, Ekurhuleni This franchise is really bad when it comes to waiting time and today i felt that something needed to be done. When we walked into the the store it was around 11:30, well there was elderly couple busy ordering then it was our turn , order taken my slip says 11:36....hardly 5 minutes the elderly couple got their order they were shocked to get their order so fast and I was excited that today we wont wait like we always do on Sundays around the same time. I must say after the elderly couple left we were the only customers for about 5 minutes until the next customers walked in....my goodness we waited ,till this other gentleman from drive through whom they asked to park and walked in to say he's been waiting for than five minutes waiting for his order outside. I told him that same here inside as I've been waiting for 15 minutes and the store is not busy at all. That time there were customers waiting to place the orders but there was no one to assist as the lady at the till was trying to pack my order after I have complained about the time I've waited. I could see that there were 2 more orders after my one in the screen. This is to show you that the store was not busy at all. I even said to the lady who was waiting to place an order that we need to call the store manager that's when the gentleman asked the lady who was packing my order to go to the tills and as he finalized packing my order. Do you think they apologized to the customers for keeping them waiting...No, not at all. I always go there on Sundays after 11am and I experience the same. Not sure if it's how they roster the staff or what but it is unacceptable to wait for 20 minutes when the store is not busy. If the store was busy I would understand. When I left the store it was 11:56. They have cameras they can verify what I'm referring to.