How do I remove a person from friendslist.

How do I remove people from my Friends List in game.

Some Random send me a friend request and I ignored/denied it in steam.

However, this name shows up in the game friend list.

I never received nor accepted a prompt in game.

There is no prompt anywhere in game that will allow me to remove this person even when inspecting their profile. 

Why are people allowed to add me to their friends list and hijack mine without my concent? 

There's plenty of things in this game that I've let slide but this is actually unacceptable.