Yesterday I was looking looking around on
www.dogbreedinfo.com. I saw a pic of a Dachshund/Yorkie. You little one reminded me of him.
http://www.dogbreedinfo.com/dorkie.htm
You still have a cutie and you can still put bows in his hairs. LOL On a serious note... I think I would be livid if he isn't a Yorkie! Not becuase he isn't adorable but because you paid for a Yorkie.
Did you get to see his mom and dad? If you have any more doubts I think I would ask the breeder about it. Good luck. Hope things work out. Just remember he is still a cutie!