hey pips, wait a minute
There are two options to be t11 friend with someone
1 -he is playing in the the same server, he send a friend request and you accept.
If you want to unfriend him, you click the remove friend button when you are in his team profile (a small - button ).
2- You 're fb friends. When you see his team. you can also read his fb name, so go in your fb friends, find him and remove him from your friends.
If you 're 100% sure that it's not an option of those above, contact with nordeus support