I had a similar problem back then… Flew with turkish airline in a Y class (eco flex) and SAS credited 25% of the miles. I argued and SAS retro team answered that my ticket is the cheapest one so I could only get 25% and this Y stands for Y for economy not a booking class. Then I sent an e-ticket with a booking class and also argued that I clearly know the difference between Y for economy and Y as a booking class. Then an agent answered back that anyway in their system it is not Y so they cannot credit my miles correctly. Then why did they require me to send an e-ticket? I even asked if SAS could credit it correctly if I could get any type of confirmation from TK but SAS said NO. so NO. No one was proactively helping me.