RHQ was supposed to be on the telecast, but when he showed up to rehearsal Saturday and was told by producers he'd be the headlining act for the red carpet pre-show ... which did not go over well with him.
Quan was pissed, feeling totally disrespected.
Quan and his people got into a shouting match with the BET honchos ... and when BET refused to budge, he bailed and went back to Atlanta.
Fans noticed his absence, with one tweeting, "I mean this a real nice put together BET Awards but um… where's Rich Homie Quan???"
He was feeling some type of way ….
Quan was like I'm outta here ….