Anyway after Kati left with the bill and money, she went to the cash register and looked over at our table, not to look at us, but at the table which I assume to see if there was any tip left for her. There was but it wasn't obvious since my brother was holding the tip in his hand. We waited 5 minutes that turned into 10 minutes then 15 minutes, no change.
During the 15 minutes, it was obvious that we were waiting since we were staring out in space and Kati walked back and forth, passing our table, taking quick glances to see if we left and she was also waiting on a few other tables around us. I was a bit pissed off because it's bad manners to not give my change back. We gave up and as we were leaving, I asked the manager what our waiter's name was and Kati was on the other side of the restaurant, saw me, and hurriedly walked to where I was....it struck me as odd because the restaurant is huge and loud and there's no way she could possibly know what I was talking about unless she knew she did something wrong.
She came and interrupted me before I could even complain to her manager. She told me that I left "too much tip". WTF! My brother said what I did was unnecessary but I think I was in the right. I think the waiter was in the wrong by not giving ME my change back. Tips are given to show a waiter/waitress they did a good job not because they're entitled to it which they aren't. I don't know, maybe I overreacted.
ETA: I wrote up a complaint letter and will be sending it to corporate headquarters and the restaurant where I dined.