^^^ There is a way to handle it. It's been written about here by those with experience over and over. Sounds like you go to a club so you're likely paying for your kids tennis lessons. If your kids coach has not taught your kids how to handle it your getting ripped off. Maybe no one said anything to you during the match maybe because your bias clouds how you see your kids line.
You need to re-read your post. You sound like a sore loser.
"i thought those were just a little harmless brown bugs, you know the ones take wings and fly? but it turned to be Flees." Fedace