This won't be a popular opinion, but I, for one, am perfectly fine with only ever having 3 refunds for the duration of your account. I've never used one, and don't see a need to.
Buyer's remorse goes both ways:
- Spend your money on something only to wish you had saved it to spend on something else later
- Return an item only to wish you still had that refund later on
I say just be more judicious with your spending, if you find yourself wanting to use refunds all the time. Try champions out before you buy them. Check out video walkthroughs of skins before you buy them to see if you think they're worth the money.
tl;dr - Spend your points/money wisely and you won't need refunds.