I was in my consolation semifinal match yesterday. It was blazing heat and the kid seemed nice enough. I was playing well, he was playing alright. Nothing amazing. Third point of the match, 30-0 in favor of me. Slice return that hit WELL inside the line (Over 6 inches for sure) but was called out. It was early on and I wasn't fuming yet so I did an exaggerated "Nooo, it wasn't." A friend and player that defeated me in the quarters was sitting on the sideline and gave me the signal that it was well in. I let it go. Flash forward to 3-2, 15-30. Backhand winner that hit on the inside of the singles line, called out loudly and followed by a "COME ON." This was the 3rd time in the match but the second that had NO chance of being out. At this point I walked up to the net and addressed the problem. "No, the ball was in. This is the second time in 5 games that you've attempted to rob me of the point. Don't let it happen again." Nevertheless, the lines apparently shifted a foot up when he was calling them and called many an ace out. I let it go because I had won 6 games in a row. At 2-0, he did it again. An ace kicker out wide was deemed a double fault. I was broken and furious. I then dropped three games in a row and had to recover. I started lobbing topspin balls back at him around service line depth so he couldn't call them out. I then got up 5-4. The final game had more of the same. 0-0, a blistering flat serve landed on the line and jammed him. After watching his return sail out, he casually said "The serve went out." I framed the second in anger and got down 0-15. It then got to 40-30, match point. Short reply gave me an easy putaway. Ball landed on the line, but was called out. Then again at ad in (And this one made me want to chuck my racket at the kid) a forehand that landed DEAD in the corner and was easily in on both the baseline and singles line, he showed the index finger. But alas, two serves later, it landed a foot inside the singles line and kicked into the side fence for match point. My question is, how do I deal with this? He only hooked on important points and a ref would've left when he saw a few games of fair play. This was the most angry I've ever been and the most accusatory I've been towards another player.