Thank you for reaching out. We offer two different types of Pause plan, one of which comes with a subscription fee and one that doesn't.
The Pause and Build plan, priced at $9 per month, allows merchants to continue to work on their store whilst their checkout is disabled. You can also pause your store and step away from it for 3 months without being charged, after which you will be moved to the Pause and Build plan if you have neither opened or closed your store in this period.
I hope this explains things, but if you're still unsure of your billing situation please let me know.
Victor | Shopify Social Care