Cant acces the in game store

when I get in to a game my champion cant buy any items... it wont even let me open up the shop. when I press p or walk up to te shopkeeper it just shows my player stats instead of allowing me to buy items... is there any way I can get around this so I can buy items and play the game. its only on my account. I have used other accounts on this pc but it wont allow my primary account.