Booked a business class flight connecting through to Istanbul as a couple. For whatever reason they did not seat us beside one another and when we asked if we could re-arrange the seating such that we were sitting beside one another (since it was a 7-hour red eye flight and we preferred to be next to each other, rather than sleeping beside strangers), they were extremely rude when telling us we should have checked in online. When we explained that we couldnt check in online since we originally booked it through another Star Alliance carrier almost a year ago, we were told that we should have come earlier even though we were the first ones in line as soon as the check in counter opened 3 hours before the flight. Instead asked us to ask other passengers around us to trade post-boarding.Not impressed with the service and lack of professionalism for an international airline, especially if youve booked business class seats. The flight to Dar Es Salaam was enjoyable, otherwise would be a 1 star for very poor service in Dar Es Salaam.