Champion Sales Bug

Ok, so I saw that Riven was on sale for 440 riot points. I bought 10 dollars worth, went to her page, and purchased. Only thing is, it costed me 880. I checked and it still says the champion is 440 until friday, and it's not friday yet. The other 2 champions I checked would let me buy then for their discounted price. I am very angry at the moment because there is no way to get in contact with Riot AND I have already used my 3 refunds. This is not an accedental buy. It was on sale, and I got scammed on the champion and I need help to find out how to get this fixed.