What to do if domain registrar is not responding?

So I have this really shitty hosting and I wanted to move everything. So I cancelled old hosting and bought new hosting and was going to move my site there. Then my domain registrar, Optimalhosting.com, doesn't work. I try to login and it doesn't let me. It just brings me back to the login page. I tried to do a password reset and they don't send the email. I sent them an email and I've been waiting since Wednesday, but still nothing. Their website doesn't have security either because Chrome flagged it as unsafe.

Meanwhile, my site got penalized or something because I am off the charts for keyword. If you go to my site, it just has advertising of my previous hosting. I emailed my old hosting and asked them for an account, but the nameservers were different. I told them to give me the same nameservers, but it was full or whatever. Anyway, my site is getting penalized like a motherf***er and I can't do anything. I worked really hard on that site and I did everything from scratch. It was my first site and I was going to use the money from that as an investment for another site.

Is there something I can do or have I lost it?

Turn off turn on
Turn off the site, maybe you are not in control of the domain yet, but you are in control of the hosting, right?
So remove the files take your site offline, before you make any more damage to it.
And in the mean time, try to resolve your domain issue.

One of the reasons why you should always go with a reliable and established registrar. If nothing works, ditch the domain and get a new one to proceed from there.