I have the exact same issue that this guy was having:
https://www.warlight.net/Forum/59591-t-decline-tournament-games

I really am not joining any tournaments, but I get invited, then they stay there, waiting on me. The "Join" button is click-able but the "Decline" button is disabled.

Is there anyway to decline the tournament invite?

Thanks,
Scotty

The decline button should be clickable. If it isn't, report it at http://warlight.net/ReportBug and include a link to the tournament.

Thanks Fizzer. I will do that next time. This time I was "force joined" and the game started. Never heard of that. Is there anyway to simply prevent getting any tournament invites? I checked settings and the wiki but didn't find anything.

Thanks again,
Scotty

From the first post it sounds like you were talking about tournaments-> you can decline those.
However, I now see that you were talking about tournament games-> you cannot decline those.

Simply put, you joined a tournament at some point- could be a very long time ago- and now you the games are created. If you don't want to play them, just join and surrender. If you're curious as to which tourney this is, you'll find it in the game settings.