The fact that they screwed up the marketing is why it is not consumer-friendly.

How exactly is lying to the consumer about what you are selling them consumer-friendly?

Exactly.

Offer unlimited. Or don’t. I don’t see why they use that word and then not honor it.

I mean slowing traffic instead of cutting them off or charging huge overage fees is consumer-friendly.

So, you mean that if they offered a product where bandwidth is reduced after a certain amount of traffic per month that would be a consumer-friendly product as compared to a product with huge overage fees?

Well, maybe.

But given the context, it's like if a car dealer had sold you a new car, then delivered an old and rusty one, and you'd be saying that delivering an old and rusty one is consumer-friendly practice as compared to billing them double what was agreed for the new one.

Also, no, this is not about "marketing language". This is about contract language. Would you also agree that there was a discussion to be had about the "marketing price" that the customer agreed to pay? I mean, the customer only intended to pay half of what they agreed to, so why should they be required to pay the full amount? Marketing language is the catch phrase that you clarify in the fine print. Contract language is what you actually agree to.