Friend List Error, I Cant Delete A Frnd

I Have about 7 guys in my friend list i want to delete them, so i right click on them and click "Remove Friend" and it tell me friend removed, after i Re-Log in or Change the Server i am playing in, i found the friend that i deleted is still on my friends and it show me also if he is online, and if i click the icon in the top at the right to remove friends, it do the same, tell me he is removed, then i find him again .. Also if i add a new friend i see him online if he is and everything is working fine with me, but most of my friends tell me i am not in their friend list although they are on mine .. This Is Really annoying, and thousands of people have the same problem...Find A Solution to Fix that Bug pls!