When is a good time to apologize such that it comes off genuine and not because you miss the friends company?

Sometimes friendships end due to incompatibiltiy of personality. I used to know one friend who thought that it would be shameful to let me know of his group of friends, ditch me, and give no reason for that. That person would counter my efforts to clarify with cowardly words like, "I don't know what you're talking about", yet send mixed signals that he does know and then when I woudl decide not to talk, he would suddenly make it seem like such a huge deal. Or say something convoluted and idiotic. I often wondered why his communication sucked so much compared to other guys. He would engage in conversations with me, then take credit for my ideas by acting like it's his own on front of his group of friends, and laugh at me behind my back. At the same time, he would find it too shameful to even let me know about his separate circle. Or, he would intentionally speak of his great fascist dictator in order to brag about the greatness of his country. I was tired of feeling pressured to go along with his constant power plays and countering one mind game after another mind game. He brought out the worst in me. Guys like that tend to show dishonesty and manipulativeness. Thank god I don't speak to him anymore. I wish I never talk to him again.