People I'm no longer friends with on Facebook are still showing up in my iPhone contacts, and their birthdays are still in my calendar

Title pretty much says it all.

I know I could disable the birthdays calendar, but I do want birthdays from the people I AM connected to to show up still. The contacts basically are no inconvenience to me as I have thousands in my phone anyway, but it seems to me both issues must be connected and it's just weird to me.