really bad customer service!!!!!

hi, my parents traveled on nov 15 2013 from ohare to Istanbul and when we checked in our bags everything was ok my parents were old and the had a carry on and I asked the attendant if we can put the carry on with the other baggage and the supervisor said no you have to pay 170 us dollars which did not make sense at all! the supervisor was really rued and was very unprofessional! what ticked me off the most is that a group of family was traveling with us on the same flight and when they checked in the bags they also checked in the carry on at no charge! when I confronted the supervisor about it she pretended she did not know what we were talking about and she denied it also she had the nerves to tell me that if u do not like how we operate do not fly with us! for a supervisor she needs to work on her attitude and show respect to customers but I thank god that this happened and the lost a frequent travelers customers never I will fly Turkish airline because of their customer service!