No you can't, the only way to receive a different prize would be if you weren't able to receive your choice of skin for some reason.
But if you are in a region that can receive prizes and you have room to accept one of the people from Mobafire you are going to get your skin chosen from the selection of the monthly raffle.
Actually if you don't want any of the skins that are being given away for that month you can pick a skin of your own choice as long as it costs up to 1350 RP. I'm not sure about getting only the RP instead, but I'll ping an admin about it!
Hey, just popping in to confirm that you can ask to swap to any other 1350 RP skin as long as it is available in store. Since you're on one of the three servers we can gift to, I would prefer if you picked a skin. We have a limited number of RP codes that we reserve to gift people on other servers like PH and BR, so I would like to avoid using one on EUNE if possible.
Jovy is correct. Any info on the raffle event is stated pretty clearly on the post= "If you already own one of the prizes, you may request it be sent to another Summoner or Address. Or if you'd like you can swap that prize out for a different prize of equal value (for this contest, you may swap for another skin priced at 1350 RP or lower)."
(from the monthly giveaway fine print)
But if you are in a region that can receive prizes and you have room to accept one of the people from Mobafire you are going to get your skin chosen from the selection of the monthly raffle.
-Thanks
It must be a sign
(from the monthly giveaway fine print)
But it's cute :D
-btw, love that picture! :D