I had this same issue try this video linked here https://screenshot.click/02-17-uv455-m4vqt.mp4
I was able to get assistance and my store was reopened last night. I received the message below.
Feb 26, 2021, 10:11 EST
Hamish here from Shopify.
Thank you for getting in touch with us regarding your account.
Access to this account has now been re-enabled and you should be able to re-add your credit card and log back in.
We thank you for your patience with this issue.
Risk Analyst | Shopify
I then went back in to pick a plan again, and the store closed AGAIN. I contacted tech support through chat, and the rep. said that he/she didn't have the tools to resolve my issue. He just kept repeating that his tools were limited.
I was on a free trial, and I haven't even been able to actually try the site out. My first impression is that this website and their tech support are not really responsive. I may just consider using Etsy.
Hope you have better luck than I have had.