league of legends rp card code , not working

So recently, i bought a 10$ canadian rp card, and when i went to redeem my code, it say ``ALREADY Redeemed`¨ (directly the first time). i bought it to a normal conveniance store, and it say already reddeemed when i only just got it and i still have 0 RP. sry for my bad english, im a big accent french-canadian.