So I'm working in the front desk of a restaurant that is a buffet and a customer storms up to me with the check. She yells at me, "Your waitress slammed the check down on me while I was still eating!" So I apologized to the customer and asked who the waitress was, and she said nothing but, "She was VERY rude! This place is horrible! Seeing how your WAITRESS was so rude and slammed the check down before I even finished eating! It's like she wants me to get out! AND I WILL LEAVE!"

I apologized for the waitress and told her politely that if she wished, she could go back to her table and continue eating food and that the waitress would be talked to. However, she just continues complaining about the fact that the waitress was rude and wanted them to get out and that the food was trash and that she would leave. Our manager has told us that if the customer insists on leaving and is complaining, we should give them a 10% discount and wish them a good day, so I do. The lady says,

"WOW, only a 10% discount?! This place is horrible and I will never come back here! And now I will have to find a new place to eat since I didn't even finish before your waitress came and slammed down the check!" Then she leaves. (Please note that she was incredibly rude the entire conversation and was basically yelling)

I'm quite happy that she left, but then the waitress comes and says that the customer had said that she was finished, but I know the waitress and she can be quite rude and has a stern looking face that some people might mistake as a "mean face". Since it was the end of the day, we have started closing and I don't know who to believe! I don't know if I handled the customer right either and have no idea how to report this to my manager, who will be there the next day. Help!