Bluetooth wont connect to galaxy s2

[Android Question]

We had to replace our old Galaxy S2. That phone the blue tooth worked fine. When we paired the bluetooth to our new replacement phone. The bluetooth would not work properly. The sound was distorted and sounds like a robot. We tried a new bluetooth, but when we paired that one, it would cut off any voice calls. I could hear music, but not any voice calls. When I turned off the bluetooth the phone worked fine.

I have tried everything I could think of. My next step is to take it back to Best Buy and replace it, Again.

Any advice.