One time I was an airport, and I didnt know that curbside baggage handler staff expected tips. There was no sign indicating that. And they wear airport staff u

One time I was an airport, and I didnt know that curbside baggage handler staff expected tips. There was no sign indicating that. And they wear airport staff uniforms. After checking in. I was asked for a tip but I wasn't able to give one because I had no change in cash. I was given a very angry look but I really had no idea about the tip. When I arrived to my destination my suitcase's wheels were damaged.