To cancel your subscription with Stock Sync, you have 2 options:

You can either Downgrade to FREE which you can do by navigating to Manage Billings and selecting the FREE plan or
 you can remove Stock Sync directly from your store, the feed settings won't disappear.

1. Go to your Shopify store dashboard.

2. On the left panel, click on Apps.

3. You will see the Installed Apps on your screen.

4. Go to Stock Sync, and click on Delete

5. Please share your feedback upon uninstalling as we can evaluate how to make Stock Sync better.