Legal Question in Criminal Law in California

I would fire your brother's attorney and get your money back.

The short answer is that they can be held as long as they agree and waive time. A person has a right to be sentenced in no less than 6 hours and no more than 20 days from their conviction or plea. Ordinarily, in a plea, since the person knows what they're getting, they waive that time and are sentenced immediately.

There may be a reason your brother's attorney is continuing the sentencing. You can't jump to conclusions that there's something wrong without knowing all the details, so advice to just "fire the attorney" are a bit hasty in my opinion.

Talk to your brother and ask what's going on. See if his attorney will let you know why it's being delayed. Go to the next court date and see first hand.