File name extension problem


I downloaded a freeware app called Quick Change that is supposed to be a simple type/creator/extension changer. The problem is that the dang thing appended all my MP3s with the phrase "No Document Selected"!!! So, for example, I have one called "birthday.mp3No Document Selected"... I haven't been able to get the developers to return my emails, so does anyone know of a way to remove this phrase from all my MP3s? AppleScript, maybe? I'd really appreciate ANY ideas; just so long as I don't have to go through and manually change about 1300 file names!!!