I cant redeem my rp giftcard

I didnt know where else to go so i came to the gameplay area thingy forums. I bought 2 $10 rp gift cards so that i could buy my friend omega sqaud teemo for xmas. When I went to redeem the card, it didnt work, I tried reloading client and doing it again and it still didnt. And yes, i was typing in the correct characters. I figured maybe the store didnt activate it or something like that, but then when I tried the second one it worked. Any suggestions for what i should do? also if it doesnt work can i get a refund?