@duckwing,
You don't, and you won't (sorry). There are 1.2 billion accounts there, and fewer than 8,350 employees - everybody from Zuckerberg to whoever empties the recycling at night. They aren't going to provide individualized help unless you are really high up (as in, "Allow me to help you with your account, Mr. McCartney.").
Frankly, I'm kind of wondering what your issue really is. Duplication of items in your activity log? Or are you having activities attributed to you that you don't recall doing? Recognize that there are offsite Like buttons, plus you might be logged into a program where you logged in via your Facebook account and allowed it to post for you (and you may have forgotten that you did that).