Originally Posted by
Polaris OBark
The motive would be to sell a bike now, rather than later. I'm not suggesting that actually happened. I am speculating that it could have happened, in exactly the same way a LBS can push someone to buy a bike that is not their size so that they can move the inventory. (Canyon, to their credit, strongly discourages buying a bike that is not the recommended size.)
Nonetheless, Canyon made a mistake (or whatever), not the OP. That much is completely unambiguous. They should do something more than simply allow him to return the bike, get on a waiting list, and meanwhile have him hope that they don't find a scratch on the frame or some other reason to deny him a full refund.
I don’t think Canyon are that desperate to shift stock, or dumb enough to think sending the wrong size without warning might actually work. It’s a bit different at the LBS when there is a sales guy trying to convince you that the bike they have in stock is the right size, even if it isn’t. Of course a reputable shop wouldn’t do that either.
I’m also going to bet that the OP gets a full refund unless they took a baseball bat to the frame out of frustration.