Sophia here from Shopify.
Responding to the email you received from Shopify was the correct thing to do. I know how important it is for your business to see this resolved as soon as possible, though we cannot guarantee a response time via email.
For confirmation that you responded to the correct email and that your message was received, you can get in touch with Shopify Support 24/7 through the Shopify Help Center. Once we have authenticated you as the store owner, we'll be able to look at previous tickets and make sure your ticket is in the right hands. Thank you for your patience and understanding.