Their call center says due to high volume they won't connect you, and I can't make changes online. My wife and I are booked DAR-IST-JFK, they changed DAR-IST from TK 604 to 605 and moved it FWD and hour and decided our flight was cancelled and did not rebook us on 605, so now we have an IST-JFK flight with no way to get to IST from DAR, no ability to make changes online and TK won't answer the phone.