If I was running a business, and someone bought a product that I didn't have, I would contact them saying that I don't have the product from the manufacturer that I had advertised, but I do have a product from another manufacturer at a lower price, or you can wait 8 weeks until the product that you paid for is available. I would DEFINITELY mention the difference in price and possible quality, not failing to mention the difference in price or quality
Why do I feel like a bad guy for being annoyed at the way this person handles this situation?