If you read what Apple TV + includes, it say Apple originals
You weren’t misled, you misunderstood.
Your subscription is for Apple TV +
Apple TV + is Apple Original content. It’s a channel found within the Apple TV App. The shows included in your subscription will have the tv+ logo on them - those are free with your subscription
About Apple TV+ - Apple Support
What is Apple TV+ and what do I get with it?
- Apple TV+ is an all-new streaming service from Apple. Watch original shows and films, ad-free and on demand, in 4K HDR and Dolby Atmos sound.
Nowhere does it say this includes iTunes movies or TV Shows, other channels, etc which are not owned by Apple to be giving away for free. Apple TV hosts other services as well as their own TV Plus. These are high quality shows.