Turn Signal Flasher Unit problems of the 1998 Chevrolet Malibu

I first checked all the fuses and bulbs to see why the turn signals were not coming on - then I found that the emergency flashers were not working as well - took vehicle in to dealer and miraculously the turn signals came back on - I explained this had happened several times since Sunday and I drive 4 hours each day total to and from work and cannot be on the freeways without turn signals (I drive to downtown los angeles and live in orange county) - the dealer said they could not locate any shorts or problems unless the signals were completely non-functioning. . . This is not safe for highway driving and I do not believe the dealer has a right to tell me to continue driving over 100 miles a day in extremely heavy traffic without turn signals and/or er flashers.