I'm sorry she had such a bad experience
but...IF you had a gut feeling something was wrong the 1st time - why did you go back ? When we trust strangers with our dogs it's up to us to read the signs good and bad....
I would stay far away from that place. No dog should come home after being groomed fearful and coughing
I hope she'll be ok. Did the vet say how serious the collapse was ??
Have you thought of doing some of the grooming yourself ?? It's not as hard as people think - I do all the basics for my girls. It saves them from having to see a groomer and me the $$....plus if I make a mistake - I know exactly what it was and how it was done...and I'm not about to cuss myself out when I DO mess up LOL - (and I have - but it's hair and grows back)
The really great thing about home grooming is you don't EVER have to worry someone abused your dog.