The workaround here is to contact Support and have them check the reason for you. You can get in touch with the Support team through live chat or email without logging in to your store by referring to this link here.
Thanks for reaching out here in the Community with your question.
I understand that you’ve tried logging into your account to update your billing information and settings but are unable to do so as your store is marked inactive. We are not able to provide or access account specific information via our Community Forums.
Best next steps are to reach out to our Support team via email with the following information:
Replying from the account owner email connected to your Shopify store.
Providing the full .myshopify.com URL of your store.
To connect with our Support team, navigate to our Contact Shopify Support page, continue without logging in, search a topic, scroll down to Continue and select the email option.