I see that a lot of people have experienced the same thing as I have, because this error is very similar to theirs.
I just bought a payment plan for my shopify site and then everything just collapsed and I got this error. I keep getting this error when trying to log back in.
Welcome to the Community! Definitely a great place to gather some input regarding anything about the platform!
With regards to your inquiry, we always refer you to your email address that you listed in this account. Please check all your inboxes for any messages from us explaining why the store is not available.
If you are not seeing any of this on your end, please reach out to our live support team for this matter. Once they verify your credentials, they can open up your account and dig deeper to see what is happening.
Definitely let me know how this works out for you.