Customer submitted a return through the site (we put in our return policy to contact us for returns but there is a way to circumvent that) - email comes to me with the request, but shopify follows up with their own email immediately after the request telling them the return request is approved. how do i put a stop to this??
The standard experience with a return is that a merchant would have to initiate the return in order for a return label to be created.
Are you using an app or custom API on your store to create this return process? Since this is something that is not normally included within the admin there must be something else in the store that has enabled these returns for you.