Parents keep complaining about my college expenses and...

I'm in my second year at the UC I'm attending, and I've been getting a 3.9 gpa in all my classes. I have thus received enough scholarships this year for all my expenses, and my parents don't have to pay a cent. This was the same as last year too. However, every time I am home for holidays they ALWAYS complain about my (nonexistent) expenses and how I am spoiled and not contributing to the family. They tell me that don't well in school doesn't mean a thing. Over break instead of hanging out with friends or other things Im taking my grandparents to doctors appointments and helping them, since they don't speak english, saving my parents the trouble of doing these tasks themselves. are just not satisfied with anything. What should I do?