rear hub noisy

I have a 99 grand prix gt. The dealer just replaced the left rear hub.
As soon as i drove it off the lot ,i could hear a grinding.Like a metal to metal sound. I thought maybe it would break in on the drive home.But, its still noisy.now, the service manager isn't calling me back. Is there a break in period on a hub?will it go away ?Or is it bad workmanship?

Stop calling and take it back. It is much harder to ignore you when you are standing in front of the window. They could have misadjusted the emergency brake or not properly installed the new assembly. Have them check the other side too, they may have replaced the wrong one!