A rock band won't give me my prize I won?!?

[Claudia Anonymous]

Hey everyone,
So back in October one of my favorite rock bands were holding a contest for the best cover of one of their songs (I won't name the band, just for privacy) and I won. I was supposed to win a free signed EP, and anything from the merch store. So after I won, the lead singer told me to email her so I did.. and she never responded. I even Facebook messaged her through the band's fan page and she said "I'll get back to you soon!!"
So, it's been about two months and I still haven't had ANY responses. But the band is fully active on their Facebook pages and instagram, twitter, etc. Not to mention their merch store too ! It's like they're ignoring me on purpose to avoid giving me free stuff. I wouldn't usually be upset with this, but this cover I made not only included a cover of the song, but a music video too. I spent a whole weekend working on it, and I'm pretty ticked off! Is there anything I can do to get my prizes? I doubt I could take any legal action. I'm just so upset and disappointed. It's like working on an A+ project and not getting your mark. Any help would be great, thanks.
And how am I to "sue them" ? I'm only 15, would my parents do it ? And what exactly for? Lol I need to know if it's worth it.