IP glitch [Client]

Earlier I was playing some games to get 1700 IP in order to get a mystery champion shard. When I finished my last game I had 1720 and went to the store in order to buy the shard. When I went to buy the shard it told me that I didn't have enough IP to buy it. So I logged out and logged back in and then my IP amount dropped to 1658. I don't know if I had enough and lost it or if the amount I had was a false amount. If this could be fixed I would be very happy.