Now, You Conferred What Degree on Me??

I got a fundraising letter from my alma mater (University of Mississippi aka Ole Miss) a few weeks ago. It was addressed to “Mr. C. David Ancell” Now, I’m not all caught up in being called Dr. Ancell. In fact, I prefer to be called David since I’m only 27 years old. However, I got my doctorate from this university. Shouldn’t they know that I have it?