It's simple math even my non business brain can comprehend, you are selling a product, if the customer is not bringing it back himself, and drops it off at UPS or if you have to send your rep to pickup it costs money.
But you decided against charging for that, as your value proposition, now that you have the market covered/cornered, you plan to go back on the value proposition. How is that not baiting and then switching. If Amazon never offered free drop off and increased the price it's a business change. But free returns is one of the main value propositions, customers fell for over other players.
No reason to be aggressive about disagreeing. I used to not charge for french fries with meal at my restaurant, now I do. Bait and switch? Or a business raises their annual subscription, is that a bait and switch. When is a business changing prices or pricing for services given not a bait and switch in your non business brain?