Well, when I first started playing LoL and got the free 400 RP, I bought Master Yi because I thought that RP was the in-game currency so, I refunded it to buy Master with the usual 450 IP. Then, I cheated a little with my second refund. I bought Volibear for 975 RP, waited for him to be on sale, then refunded and bought him again for 487 RP. Then the last one was to sell a champion I didn't like as much to buy another one which I prefered.
I would like to have more refunds since I have skins I hate and never use, especially the Mistery Gift ones, but that's another story. I started playing some champions less, or I realized the skin wasn't what I expected and that there was a better skin that I liked for that said champion. This is the case, especially with VUs, although the VU team does an excellent job with Traditional skins and keeping the overall theme of the skins and making them better.
I would like to ask for more refunds or limitless refunds, but I do understand why there's the limit (buying a champion or skin for full price then waiting for sale to refund and buy it for less is not fair for you guys in eMarketing). I personally have spent 300€ in LoL and I'm still waiting for the RP lifetime reward you guys have promised, but I would love it to have more refunds depending on how much RP I have spent.
Maybe you could do that, or make it so you can refund everything you buy but for a more limited set of time, although I would like to have the option of refunding skins I bought MONTHS even YEARS ago. Refund tokens every season maybe? I don't know if that's even plausible but I'm just suggesting...
TL;DR: I spent my Refund tokens on something I didn't want to buy, to buy the same exact item from the store on sale, and to refund a champion I didn't like that much to buy another one I liked more. I'd like to have more Refund Tokens in some way or form, if plausible, especially because I have spent so much money on RPs.
And as for Mistery Gifts, it would be awesome to have at least a chance to reroll the skin we get.