Wheel bearing?
 

I just had the wheel bearings on my 05 sebring replaced about 6 weeks ago. Now my car sounds like the bearings are going out again. This time though, it doesn't matter whether I turn or not. it's a loud grind/hum, and a slight vibration in the steering wheel. Its not there when idling, and quiets down a bit when accelerating over 50 mph. Does anyone have any idea what it could be? I'm stumped!

Trying to diagnose a strange noise via internet posting is basically impossible. If you suspect the repair has failed, take it back. If they give you a hard time, you might have to pay for a second opinion.