What can I do about my parents and my 10 month old dog?

I have a 10 month old dog that is a Labrador, Shar Pei mix. And parents that keep him outside for just about the whole day. He is only inside from about after 8 P.M. until about 6:30 A.M. So he really only sleeps when he is inside. My parents say that dogs belong outside, and he doesn't need to be inside. He hardly gets any attention because me and my brothers are at school and doing stuff after school, my dad is at work, and my step mom works at home but usually only goes outside with him to feed him. Recently he just destroyed all of his toys, and my parents don't realize that he is a dog. Not a human. They won't buy him new toys anytime soon because they say that if he is just going to destroy them then he doesn't deserve any. So now that his toys are gone he has been digging holes and making my parents even angrier. Shouldn't dogs be excited to go outside? That isn't the case with mine. Whenever they let him in he gets so excited that his tail wags so hard that it bleeds when it starts hitting walls. Whenever we stay at my grandparents house he is inside just about the whole day. Whenever he is inside the whole day, he doesn't act up at all. And my parents don't realize that. It makes me angry the way my parents treat him, and angrier that they think it's the way dogs are supposed to be treated.