One would think being R. Kelly's brother would be a good gig.

According to Bruce Kelly, that thought would be completely wrong.

Bruce claims that his younger brother hired him to be his personal assistant and driver at the pedestrian rate of $700 a week. Then R. proceeded to work his fam 144 hour weeks -- which comes to $4.86 an hour.

And how did Bruce -- who's filed a complaint against his brother with the State of Illinois Labor Board -- get to 144, considering there are only 168 hours in an entire week?

Apparently, R. would make B. wait  in the car for him at stretches of up to 12 hours, keeping B. on the clock and preventing him from getting any proper sleep.

Additionally, Bruce is claiming his brother didn't even pay him the money he owed him (11K), and that's why his submitted papers with the labor board.

Bruce told TMZ that he's "not working for nobody, not even his brother, for free."

R. Kelly hasn't yet to respond to the charges.