To come back to the original problem.
The Aircraft wasn't X, Y or Z, but Q.
However, they managed to arrange that it shouldn't be my concern anymore, as they gave me different issues....
I get in the morning a message that the leg K-BL-IST was cancelled, as it wasn't confirmed within 24h to departure. (it was ticketed of course).
PAX had to buy his way out of there for almost $2000 ! (its says commission $600+ on the receipt - whatever that means).
I called UA, and told them that they issued that tickets, and as needing to reconfirm a ticket isn't a standard since quite a few years, in fact airlines have such an option over the phone: "if you want to reconfirm you flight press # 2" "Flights no longer need to be reconfirmed..."
UA says that they do not get notified of such rules, and even when telling you eg to be 2 hours before a flight to the airport, its just their advice, but really one needs to call up the operating airline.
BTW, i was hours with Turkish on the line, and no one mentioned anything of the kind.
As I knew that Turkish and United will just push the blame on each other, I've asked them to put the complaint up by star alliance.
I've been asked today to send the original receipts.
Will see what happens...