As MDS says, you need to check the settings on both the player and the TV to get it right. Since it was also a problem with a commercial, most likely your problem is a TV setting. It might be labeled "zoom" or "aspect". Check the manual for the TV, and go into the menu to set this how you want it.
TVs are typically made so that you can keep everything undistorted and uncropped, or you can set things to distort and/or crop in order to fill the screen. Some people want their big screens full, no matter how bad it ends up looking.