boobs

So these past couple weeks I've been getting kind of bullied at school and it's really making me sad and angry at the same time.and it's never the girls who talk about me. It's ALWAYS THE BOYS. And I'm new to my school this year and all the boys are talking bad about me because of my boobs. The say there "flat" and "not good enough" I'm in a B cup. and these boys are expecting these 8th grade girls to have these huge knockers.  And the came up with a song for me. Which is... " Roses are red, Violets are black, Why is your chest as flat as your back?" And it's getting to the point where I can't take it anymore. And I don't know what to do. I've tried ignoring it! But it just doesn't work. What should I do?