I had the same problem with my transmission after it was serviced by Carmax. The transmission has an overflow valve on it. If the transmission is overfilled, this valve opens to allow the excess fluid to bleed out to prevent damage to the transmission (brillant!!). The bleeding went on for days. It took it back to the dealer and they did admit that it was overfilled and corrected it by draining and refilling it. I have had 0 problems with the transmission since. This could be your problem as well, especially since the fluid was pink. Like the other guy said, you should get a second opinion. Most shops are only interested in profit only. Always check around.