I think you should *proceed with caution* in a situation like this. Maybe you could contact this company somehow and ask them what they're copyright and patent policies are. Other than that, I don't know what to tell you. In order to patent something you have to have a product, not just an idea.
My suggestion to you is to be very careful, and to get it in writing, if at all possible, that this is your idea, it is an original idea, and that you came up with it, and then shared the basic concept with this company WITHOUT giving them authorization to use it as a product without your permission. Get it notorized if you can. I don't know that there is any kind of document like this online,
but even if you simply write it up yourself and fax it to them and have it faxed back so that you both understand the situation. If they don't want to tell you their copyright and patent policies, or if they are unwilling to cooperate with you, I would not continue to deal with them, or at the very least become suspicious of the company.
I'm not a lawyer or an expert in any way, so please don't take my suggestion as if it were legal advice, it's just that, a suggestion based on my personal knowledge and common sense, but feel free to use it as you will, and I hope that I have helped you.