You're bending a lot of terms to fit your arguments.
If you don't know something that is common knowledge, you shouldn't expect to be catered to. It is rare, if not nonexistent, to find a telecommunications company offering a free phone with no contract; if there was, then your "confusion" would be justified. I think there is a very good chance that you *do* know that anytime anybody talks about a free phone it is always free on contract; you simply choose to complain about something that is common. The term is curmudgeon.
None of those examples are incorrect. Offer does not imply free. Rarely are prices quoted for products include tax unless specifically stated. And yes, if you return a product for a refund, the sales tax is refunded as well.