Can't purchase Vi with Riot Points

Hi there,

Earlier today, I noticed that Vi's Price (RP) is 975 on the store but once u go in her page its only 487rp , as if she was on sale. so i wanted to purchase her but then it pops up an error saying "Your purchase could not be completed at this time". i think the cause is the fact that the prices don't much.

I will very much appreciate it if u fix it, Ty with all of my heart, IshyMoto