Why can't I refund my Team Liquid icon?

I joined the Team Liquid bandwagon after their 2-0 week 1, so I bought their summoner icon. Since they've gone 2-4 in the weeks following those promising first two matches, I've lost interest in the team, so I went to my purchases to refund the icon, but it says it's "Not Refundable." I only bought the icon 21 days ago, and I really want to get that fancy looking Firecracker icon