Gankgplank champion purchase bug (Client)

I recently purchased Gankplank so I could get the free skin, and I have an issue with the purchase, if it can be considered an issue, that is. What happened was, I collected IP to buy the Champion, and some more on top of the IP that is needed, 4177 IP to be exact. I purchased Gankplank, got the Champ, and my IP was not deducted. I dont care much if my IP does get deducted, I collected it so I can spend it anyway, I just wanted to report the bug that I experienced.