How Do I Get my Doctor to Give Me a Referral?

I'm 23 years old, weigh 105 lbs and 5'2. My breast size is 34DD which makes my body appear very disproportionate. It's not just the discomfort but I also have back, neck and shoulder pain and I don't even want to mention the emotional problems. I gave up ballet and every other physical activity. My doctor refuses to refer me to a plastic surgeon because he thinks breast reduction is to invasive to relieve such a "small" problem.