That's legal and reasonable. You aren't even required to offer to send them back, although it was nice of you to do so. I definitely see a distinction between a package addressed to someone else and delivered to my house and a company sending a package addressed to me with unordered merchandise. For the wrong address I'd get it to the right person if that's easy enough or contact them if it's not convenient for me to hand deliver. For unordered merchandise I would either keep it, give as a present, or donate to charity.