Can't Use Refund Credit

Okay, so on my second account I use to play with my friends that are new to the game, I wanted to mystery gift a new ward skin since it costs 380 RP. Well like an idiot I got the mystery ward for myself! I tried to refund it since it technically doesn't count as a gift but it says 'Not Refundable' right beside the ward on the Purchases tab. I don't know if this is an unintentional bug or what, but I'm kind of upset over the fact that I still have TWO refund credits available and I cant use them. On your refund policy board it says you can refund wards.