Hardly. Apple created a system within their TV app where they have partnered with providers so they can host their content and have an option for consumers who want to use one app to access content. It is very clear that this is a separate subscription from the one that is offered directly from the provider.
As stated Amazon also offers their own channels and the same would apply there, as would it if Microsoft offered a channel system where they host content from 3rd party party providers within a central app.
Bottom line is you subscribed to a service under two distinct platforms without thinking it through, you can realize what happened and take the time to explain the situation to get a refund. If you'd rather not and just rant then that is your choice. However, I will now be bowing out of this discussion. Have a good day.