Remove Facebook birthdays from iPhone calendar

I know this question has been asked all over the internet several times (including in these forums) but none of the guides have helped me so far so i thought i would give it a shot.

How in the **** to i get rid of all the Facebook birthday entries from my calendar? I dont have a Facebook calendar in my calendar settings that i can uncheck, and when i uncheck the native "birthday" calendar all the birthdays are still there. The reason why i think its from Facebook is because i´m fairly certain that i synced them a long long time ago, and also because there are people in my calendar that are not in my contacts app (There are no birthday entries whatsoever on any of my phone contacts).

So how do i remove these? I´ve looked in both my phone settings and Facebook settings for anything sync related but I cant find any.