Can't redownload lol mac client

While playing at my mac, the fps would drop to 20 from 80-100 for like 1-2 minutes like every 5 mins, so i decided to delete the app and redownload it. But now, it looks like i cant. I can go through the download now pages, but once i click the download button, it doesn't load. I have been trying to solve this problem from yesterday, even the support.riotgames isnt loading, i hope you guys can help me thanks