Ivy here from Shopify.
Can I check if you are now able to access your store and admin at the moment? If not: The first thing I always recommend in the case of not being able to access your store, is to make sure this is not a local issue with either your device or browser as this often is the case. Here are the steps to follow to check this:
Clear your cache and cookies on your browser. After this, completely reboot the browser.
Try on another web browser or an incognito window.
When using incognito, if you are still experiencing a display issue, confirm you have disabled browser extensions as these can change how the pages look.
Try another device or on the Shopify Mobile app.
Try another internet connection (example, switch to a cellular network on a phone rather than wifi.)
After this, if the problem persists the next thing to do is to check that there is not a current known issue or outage with the Shopify platform. You can check this anytime at the address www.shopifystatus.com, this will always give you accurate and up-to-date information on the status of Shopify.
If after all of these steps you are still having issues, then I would recommend at this stage to reach out to our support team as they will be able to access your store to investigate what is going on. You mentioned you had some trouble accessing phone support - phone support is not always available. In instances where there is a longer waiting period , we may re-direct you to chat support to ensure you have your issue handled in the fastest possible time. We always have access to live email and chat at our support portal here.
I hope this helps! Thanks, Ivy.