This is Lana from Shopify.
If you no longer have an active subscription, you would need to look into reactivating your store and paying for a plan in order to look into your invoices. I can understand that you may not wish to use the subscription, so after you have downloaded your invoices, you can close your store again and enquire about a refund with us. Your invoices are found in the Settings > Billing section, where you can click on View billing history to see all past invoices.
After you have downloaded them, if you wish to close the store to be eligible for a refund, you need to take the following steps:
From your Shopify admin, go to Settings > Plan.
Click Cancel subscription or Pause or cancel subscription.
If you still want to cancel, then click Cancel subscription and close store.
Select a reason for the cancellation, and then click Continue.
Enter your password, and then click Close store.
After that, please contact our support here so that we can look into a refund for you. You will need to go through that link because at the moment we are unable to look into your account details via the Shopify Community.
Let me know if you have any other questions!