I'd suggest what you need to do, but I'm afraid that you'd think my advice was bad and end up suing me.
Grandmaster gave me the wrong advice

GM's have a legal obligation to give correct training and advice.
Where did you get that silly idea? Certainly not from any law book on planet earth. But as I said, let's see the games, so we can see how the grandmaster's advice was the cause of your defeat.
I will post soon. You will see.

I for once agree with OP. Grandmasters should give perfect advice or have their title stripped.
ok so they just stop giving advice then. I would not risk my title becouse some stupid nobody want some help.
Only case you have is if you payed for tuition, but then you would have to take a GM to court and prove him wrong. If you can do that Im guessing you would not need him as a teacher anyway

A Grandmaster once gave me great advice, he said " Look out Kay, a bus!!!!"
At last! Hurrah!

Maybe he got to be a GM by giving lots and lots of people bad advice?
Probably true. We need to give away all our bad advice so that it all gets out of our bodies. Then, and only then, we can be good at things.

His name is ThrowThemInJail he just joined chess.com today on August 1, he's unrated and he wants to sue a grandmaster. Do I smell troll!

Recently, a grandmaster gave me the wrong chess advice. As a result, I lost a tournament. I am thinking about filing a lawsuit.
what kind of tournament and how much money was on the line.
what kind of advice. play c4 in this position?
isn't it possible the chess advice wasn't wrong. Maybe you just played it out wrong?

His name is ThrowThemInJail he just joined chess.com today on August 1, he's unrated and he wants to sue a grandmaster. Do I smell troll!
yes I think you do. Still Im biting, this is to fun

If you can prove the GM purposefully trained you wrong as a joke or that he didn't have the knowledge he claimed I think you might be able to make some fraud charges stick. He probably wouldn't see any jail time but it's worth looking into. Contact a lawyer and punch him in the nose. That should make you feel better.

oh oh oh I bet the advice was "win" he lost thus thinks the advice was bad lol ... they see me trolling trolling trolling.....

It's August 1st, not April 1st.
This could be the very first chess grandmaster malpractice lawsuit in history.

If the op had included the specific piece of advice that the nameless GM gave him /her then we would be in a much better position to comment on said advice..as it stands the op has no case because no evidence has been produced..case dismissed!.

What was the advice? Is it possible you could have missinterpreted it? Unless you were paying him for lessons you have no legal case for taking him to court. That would just be a waste of your own money. But I highly doubt he gave you bad advive. Most likely you just missinterpreted it. If you are good enough to win the competition dont you think you would have noticed that the gm's advice was wrong? I dunno, your story has holes in it. Id like to see the games and hear what advice was given to you.
Recently, a grandmaster gave me the wrong chess advice. As a result, I lost a tournament. I am thinking about filing a lawsuit.