It sounds like you need an exortist not a trainer
Seriously, how old is your scamp? If you are getting nowhere with yelling, have you tried shaming him? If I ever yelled at Sawyer, he would probably think it was a great game; but if I shame him, it really gets his attention. Yorkies really do usually love our attention, and he seems to have found a way to get plenty of yours. If you shame him, and then ignore him for a few minutes he may get the idea of what it takes to get your attention in a ggod way. Good luck