Join their slack to get in touch with the community:
https://steem.herokuapp.com/

Afaik, there are several people reporting the same issue.

Hi, there's no steem forum to ask this so I'm asking here. I am having a lot of trouble signing up. I entered my facebook in but it says I can't register twice.. But when I try to log in, it says my account doesn't exist. No idea what's going on but I wanted to buy some and participate. What should I do?