@BakaOji Might want to shut up, you're letting the stupid leak out.
It looks like there is some issue with Steam-only users being able to log-in to the support site. If you linked your Steam account to a MS store PSO2 account, then you can just log-in with your Microsoft/XBox account at the support site, but otherwise it looks like it is just a matter of waiting until they fix that.
Also, the support company is American. There might be no support on the weekends.