Giving users options to opt in or out of messages improves your user experience. Below are three suggestions for unsubscribing users.
Add the ShopMessage recommended Messenger Menu setting, "Manage Notifications
Adding this recommendation will auto-add a message to your Menu that gives users the option to subscribe or unsubscribe.
Since the Messenger Menu is always accessible to users, this is the ShopMessage recommended solution.
Include an unsubscribe button in your flows and campaigns.
This allows your users to unsubscribe with the click of a button. Learn how to do this here.
Direct your users to turn off messages from your page.
The best way to ensure that that these users no longer receive messages is to have them Turn Off Messages from their Messenger settings. Here's a GIF that shows how to do that. Please note that this is the Facebook recommended solution.
Take an action from your page to block the user.
Here are the Facebook instructions to do this:
Click Inbox at the top of your Page.
Click the message on the left from the person you want to ban.
Click in the top right and select Ban From Page.