Called me, I did not answer, they left no message

This number called me.  Left no message.  I think it's from a medical school that I had once asked for info from.  A LONG time ago and they are still calling.  Luckily, I have a call block feature on my phone!

They called AGAIN, 2 months later... again no pickup, no message.  If it was important they would have left a message