Ted here from Shopify, thanks for reaching out to us!
Great question! We can never guarantee a refund without having a closer look at the account first. That being said, if you've received an invoice with just the subscription fee, it's likely we'll be able to issue a refund. If you would prefer, you can always pause your store as mentioned in this guide and continue to work on it if you would like? If not, you can close your store as shown here and I can take a closer look at the account after and review everything in full.
If there is anything else I can help you with, please let me know, I'm happy to help!