There is a reason why moderators don't want this kind of thing posted on the forum. It could just result in finger pointing from both sides with baseless accusations. You claim your opponent froze the game on purpose. They could just as easily create an account here and say the same about you.
If you have an issue, report it in game or use https://theshow.sonysandiegostudio.games/hc/en-us/requests/new
If you have a chat log or other evidence that he froze the game on purpose, you could attach it. If you don't have that, then him intentionally freezing the game was likely an assumption on your part, and while proper etiquette is for the losing team to quit, a lot of people don't follow that and try to win at all costs. I've been stuck in plenty of freeze offs with those types of people, and I agree that it sucks. All online games with a sizable player base will have some toxic tools.
Freeze offs in MLB The Show have been going on since at least 17 when I started playing Diamond Dynasty, and clearly SDS has not been able to prevent them or come up with a reasonable solution. I hope they're continuing to work on fixes and maybe a more elegant solution than two people twiddling their thumbs for hours on end waiting for the other to blink, but I also won't hold my breath.
As hoboadam said, you're just going to get put in the time out chair. If you want a chance at actually seeing results, do it the right way. This forum post will accomplish nothing.