It's kinda funny with e-payments like in games and such. Riot clearly CAN give refunds within a certain timeframe since they have the option already implemented, but then they just stop at 3 as if the product we bought is static and won't change. It's like buying a banana that a farmer can randomly change into a kiwi later on after I bought it i.e. reworks and nerfs to champs and skin designs.
I haven't seen these ever refresh despite reworks and new champs/skins being released that it'd be viable for. It's not like we get our money back, just our rp to spend on something else. They already have our currency, so it shouldn't matter if they refund the rp to spend on something else.