Help pleas!!!

Ok, I'm 16, have no credit card, I have a recently purchased $100.00 DOLLER ITUNES GIFTCARD!!! I've searched answers, none helped, but I went to redeem my account, i put the exact code in, (it's clear and easy to read,) but it says invalid, or inactivated! I tried all the answers I found online I tried everything. No matter what, it won't work! I need help!!! I can't figure it out, and as you all no, THERE'S NO REFUNDS ALLOUD!!! I lost $100.00! The code was unscratched, there's no explaination, I've givin up, will someone please help?!? I tour up my room, looking 4 the receit, nowhere to b found, might of thrown it away. I have the card, and the hole in my pocket to prove the purchase and that's it. There's nothing I know of that I can do, any suggestions?