Retards...
Okay, in "Case of the Misplaced Mike" Pac is not talking about Mike (a person), he's talking about a mic... a microphone.
I hope you were joking about the "I Ain't Mad at Cha" thing... but if not, "Cha" is like "ya" or "you"... but if you say "I ain't mad at ya" quickly and fluidly enough, "ya" makes a "cha" sound.