Refuse to assist pregnant woman with Dr's note

I am currently 14 weeks and 3 days pregnant. With a low baby. I have a Dr's note as per Kulula's request to say I may fly with assistance as I may not be bumped or shoved and may not go through the scanner. When I booked the ticket through King Shaka they said I need to be there at least 2 hours in advance to book seat and organise everything. They could not put me next to a window but refuse to help me as they have put me in the isle now I have to move for other passengers and take the risk of being bumped and shoved. And were spoken to in a rude manner about it instead of making a plan and assisting me. Then told me it is my responsibility to ask other passengers if they would be willing to give up their seat for me when it should not be my or their responsibility while risking being pushed and shoved by other passengers. Doesn't matter who I spoke to from checking in nobody was willing to help and is full of excuses why they cant help. And each person I spoke to had a different story and excuse which in the end did not make sense and add up. They were so unwilling to assist I ended up in tears.