First, I have to say the customer service from Shopify is absolutely abysmal at this point. Just recently I cannot log in to my store when I try I get the following error "There's no matching email for this store", would appreciate some help here.
If you've ensured that you've inputted the correct email address that is attached to your store, are you able to try logging in on an incognito mode or private browser window? If the issue still persists, you can also try logging in from another device altogether, just so that we can rule out any browser or caching issues.
However, if you're still running into issues, you can reach out to our internal Support Team so that we can take a closer look at your account. It sounds like you may have had a frustrating experience previously with our Support Team, though I can assure you that it's in our best interest to help our merchants. To look into your login issue further, our team would need to securely access your account, which at this stage isn't supportable via the Shopify Community Forums. So we'll need you to visit ourHelp Centre hereto start a support request. You can click on the Continue without logging in button, search for a topic, and scroll down to click on the Continue button under Get Support. From there our Support Advisor team would be happy to look into your issue either via chat, or email.
Kimi | Social Care @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog