Terrible customer service

This is the first time writing a review on this website but I am so appalled by the terrible service of Fastjet I felt I needed to say something. I live in Tanzania at the moment and booked a flight for my family of 3 to South Africa for a holiday. During the trip we found out my son had to have an unforeseen operation and therefore him and myself would not be able to fly back on the scheduled date. I sent the doctors note from the hospital to them and explained the situation to which I was told they could not do anything and I would basically have to pay for another ticket. Now if this is their policy then fine, I don't agree and will try never to fly with this company again because of this but when my husband asked to speak to the manager the lady on the phone came back and said he would not speak with us and there is nothing he can do. This is quite possibly the worst service I have ever received, when the manager couldn't even be bothered to speak to a client, clearly it is not his own business and he couldn't care less. My advice to anyone considering this company is think twice as they have no idea about customer service. Mango airlines on the other hand were AMAZING!