Don't give him your tax ID number. He doesn't need it. Even as an employer/contractor basis, the work is already done with no contract filed before hand - therefore (though both of you are legally liable), you don't have to give him that information. If he infact required it before hand, he would've asked for it.

The fact that he is a for-profit group gives you leverage. You now have the basis for suing since he is a registered business. You need to talk with your parents, let them know the situation, and if everyone deems it worthy, you could have some sort of legal support on your side.

However, like I mentioned earlier - with no contract, there isn't much you can do - but the fact that he is a for-profit, not giving you money, should give you some power since the consequences of not paying you and receiving penalties to his own company far outweigh the money he should pay you.

To me - it's a load of BS. REAL companies will present themselves in a professional manner and not like this. Either he's wasting your time, or he's looking for personal information to do some more serious damage (such as identity theft) then what he's already done.

Or you can cut your losses. Sell the template, get some money back, and walk away from this with a lesson learned.