Bring it back again tomorrow and get a NEW replacement- make SURE it is not a refurb- you can tell by whether or not it comes out of one of the ORANGE at&t boxes. A refurbished would be in a generic, probably plain white box. Often times replacements will be refurbs, which have had previous problems and fixed.
Think I nailed this one, robk31569! No other reason made any sense to me- the chances of getting multiple phones, especially Berries with their fine track record of quality control- with the same exact problem didn't make any sense. Make them get it right tomorrow.