This sounds strange. I think maybe a Porch / Parcel Pirate situation has happened. The is no chance amazon would even notice the wrong item was sent or if they did notice which is very very unlikely. They would contact you and ask you to pay the difference or maybe some other agreement. Am thinking this was either a stolen parcel from a outside delivery left on a door stop or a delivery driver selling items off the back of the lorry or even someone in the warehouse sending out deliberate wrong delivery's for cash. For example order a cheap ps4 I'll make sure a ps5 is sent out just pass me some $£$£