Qatar Airways — Not allowed to board flight

My route to reach Baku was lhr to Doha turn Doha to Baku but my return flight was from emirates Baku to Doha then Doha to lhr. Kindly guide me through a written policy why I have been not allowed to board flight by your representative. I had an appointment for my visa at Lithuania embassy at Baku.After waiting for 6 months got this appointment but due to your inconvenience the appointment as been cancelled and I have to wait for my next appointment… whom should be considered responsible for my time waste and money waste on the non refundable return ticket ?