Complaint about IM-Contest?

I have taken part in a certain contest in the IM-field and have not yet received my prices or even a notice when they might be sent out.

On monday this week I sent a mail to their customer service and gave them until the end of this week to come back to me with a definite date or answer as to when and how they are going to take further steps to get the prices to the contest winners.

I have not received an answer yet. I believe that giving them 5 days would be enough to respond to a mail.

I know for a fact that another winner hasn't received his price either, while he is living in the US, I am not, so I don't expect my price to come fast, but within the US it should be a matter of a week or two.

Before my last mail, I had sent another mail and got the answer that my request would be forwarded to the appropriate department... yeah, as if.
Haven't received an answer for another two weeks or so, that's why I sent the last mail, telling them that I would take further measures if they would not finally respond with a definitive answer when they'd finally do something.

So well, I'd now like to inform myself how I would be able to take legal steps. I believe that a friend told me about another contest holder being forced to hand out the prices to the winners by some organization, but this friend didn't know anything more specific.

Long story short: Where could I file a complaint about the way these people handle their contest winners to make sure that everyone receives their prices?

It is a big company, by far not a one-man-show, so I'm absolutely sure that they have the capacity to send out a few lousy prices and I'm sick of being handled like this.
Especially from people who claim to belong to the good guys.
I'm sure the people of the JV launch got their motorbikes and thousands of dollars within a week or two, for the rest of us it has been two months or so and still not even the message of "we'll send the prices out on xxxx".

I could go on, but I think I made my point clear.

I'd be very happy if someone could give me some hint to where I could turn to get what is rightfully mine

(best case would be without involvement of a lawyer of course )