If this is the only document you have signed it is a fairly loose agreement. It is basically signing over the payments to a finance company which is bad, but the good point is that it doesn't refer to any RULES which you have to conform to. As such, many of CXT's suggestions come in to play.
The only contractural element I found which may be worth pursuing is;
They are clearly a Taekwondo school. In fact in point 5 they state that the payments cover taekwondo training only. However, in the programs you may participate in, they have ticked Cardio Karate.
I would take a couple of Cardio Karate classes (if you know a karate friend who can come and watch, so much the better) and then question the instructors qualifications to instruct. You could question what style he does, what rank, and which organization he got his KARATE grades under. Chances are, he's a taekwondo guy rather than a karate guy and if so they may be guilty of misrepresentation.
If they say, Oh he's a TKD guy but it's the same as karate, it isn't.
If they have misrepresented themselves, you need to go into writing stating so. It's going to be a fight, but hey, if you're going to have a fight have a good one.
$7,795 for 3 years!!
That's $2,598 a year.!!!
That's $216 a month!!!
(And gradings are on top!!!)
That's a ridiculus rate and I live in New York!!!
Other people may have other suggestions, but let us know how it goes.