Pathetic,Bad & Poor cust service

Me &my friend Thandi visited Mcdonald today to buy lunch &were helped by the cashier Babara Kavumba which was very friendly we bought 2xmcfeast &BBQ double & sit down to eat &after a few min Sarah(assistand manager)came &ask for our slips we asked her why she want it,she couldn't answer so we gave it to her cause we thought its might be for a competition.after she left Jeffrey Maluleka(branch manager)came to us with the same slips & ask us for our details i refused,cause since when do u give your details @ restaurant exspecially if u already paid for something. They assumed that we didn't pay for the food.It was so embarrassing &humaliated,cause eveyone was looking @ us as if we were ******,why did they choose us amoungst all those cust who were help by that cashier,they should sort their problems out between them & not involved cust in their issues,cause at end we are the one's that make it possible for them to have jobs & get paid without us they are jobless,but surely Mcdonalds kolonnade doesn't need us as cust. It was my first time buying from Mcdonalds & with the bad treatment I've got,surely my last.First impressions count after all.So,so dissapointed in their bad service.