Unable to Buy Champs(gameplay bug?)

So first i want to say I'm not actually sure if this is a bug but its definitely not working. So this has been happening for a while now and i thought it was just the new update at the time but that's been few months now(i cant remember exactly when the update was) and i have asked other people who say they can buy champs just fine. So what happens is i will go to a champ i don't own and go to the unlock button and when i put the mouse over it it says "not yet implemented". I know its not a IP problem because i have more then enough(44,128 at the moment). Is anyone else having this issue? Why is it happening?