Thanks for the great suggestions. I finally did get through to Turkish Air and to someone who understood and spoke some English. He pulled up my e-ticket and confirmed that indeed I am holding business class tickets. Found out that the class codes K,C & J are business class. Thus GCT only erred in the air itinerary printing in booklet. How grateful I am that GCT got me direct flights from LAX to IST.
Pauline, thanks for your posts about Global Entry. I enrolled having read yours and will be experiening the advantage with this trip. While I have known about GOES since it was first marketed by AMEX I never showed any interest until I started following the OAT Travel Forum.