Based on my experience, booking over M&S hotline by phone works smoothly. BUT: So far ticketing by local TK office ALWAYS failed. At ZRH office, they always managed to retrieve the booking within seconds - but always failed to issue the ticket even after asking the supervisor, the supervisor calling Istanbul etc etc
I don't want to blame ZRH staff, they really went out of their way. After a while, all staff present were involved ... but without success, I'm afraid ... They were very apologetic, but this didn't change the situation.