Shop is not working for me.

The shop is a bit bugged because I have 6404 IP but it wont let me buy a 6300 champion. I restarted my league launcher to refresh it, but when I went to the shop it still wont let me buy a 6300 champion. I played 1 more game to increase my IP. My IP is now 6537 and stiil cant buys 6300 champ. RIOT please fix this.....