This really gets me:

  I was given pretty much no feedback

This is exactly what happened to me a few years back. I was so eager for that review since we had all our KPIs recorded and I knew I had a perfect record, and all I heard was something along the lines "I have nothing bad to say". In that review, my manager said my results would warrant at least an A, and a promotion would probably be on the way. Probably.

A few weeks later I received a letter with my C rating, and I left the company a few months later.