Mobiles and facebook

I finally relented and bought a mobile, have set it all up and did not even touch the Facebook link.
Haven't been on fb for ages and no longer have an account.

For the last few days I have been getting text messages from Facebook asking if I know these people, my friends commented on stuff and one even called me by a name that is not mine!

What on earth is the go with that?!
Why is my number being spammed...it is new and the only web page I have visited is this one!