Rude Customers

I recently started working at McDonald's today was my third day. I was doing the register and a guy comes up i take his order and when i hand him his receipt i dont know what he read and he get mads and yells at me "you know what i want my money back" i have no idea why so i call the manager he tells the manager" i want my money back i asked for a meal and she cant get it right" the manager takes a look and tells him "you do have a meal its a large fries and large drink" he was like oh ok and walks away without apologizing. So today i realized how rude people can be to you for nothing...