I agree this can be frustrating.. but it isn't fair to be so upset with someone for that. The better solution would be to only join tournaments that have the time limit to your liking. This person probably signed up for a 7 day limit because he needs it. He is well within his rights to do this. If this angers you so much, you should sign up for tournaments with a 1 or 2 day time limit.
Just a friendly piece of advice. :-)