What happened to customer service

Today i went to go do my last Christmas shopping, and decided on Steers for lunch. Biggest mistake ever. I waited 40 minutes for 2 Rib burger meals, Double cheese (which was all cold except for the chips) meal and banana milkshake. While waiting for my food I observe the girl giving the food wiping her nose twice without even considering to wash her hands. When i got my food I was given warm cool drinks with no apology my milkshake was watered down. When I asked that they make me a new one the white guy at the back screamed at me to relax. This made me livid, really so I have to be happy with sub standard service and food but you expect me to pay full price. I'm sorry when I decide to buy fast food it needs to fast and I need to get value for my money. I feel disrespected and want a senior person to contact me cause clearly the manager has no regard for customer service.