Misleading - MSC Cruise and Sure Travel

We have book a ship cruise in July 2018. On paying our R3000 it was told to us that this amount paid was to secure our cabin on the ship. We were issued with a receipt only. During the end of 2018 my 2 year old girl was diagnosed with severe asthma and sinusitis. We were then told by our family doctor that we should not be allowed to travel with my 2 year old as the different climate change would affect her badly. We then decided to cancel our cruise due to her illness. I then contacted Sure Travel in Newcastle as the have done the booking for us to notify them that we would like to cancel our cruise. Ms Hummaira from Sure Travel took my call which I did advise her that I would like to cancel due to my little girls illness. She then told me I would then require to get a medical certificate from my doctor. She did not inform that the deposit is not refundable. I got a medical certificate from my doctor and dropped it off at Sure Travel Newcastle. Hummaira then said she would let me know. After a few days she then tells me that MSC refuses to give back my deposit regardless of my kid being sick and with a medical certificate attached. She then advised me to contact MSC directly which I did and an extremely rude lady Angela refused to help me and told me she refuses to deal with but with Sure Travel. Sure Travel then advised me that MSC refuses and say that they will only consider giving me a refund if my child is hospitalised on the day of departure. The fact that the travel agency didn't not inform me that the deposit is not refundable and advised me to get a medical certificate in order to get my deposit back. Sure Travel and MSC are not very efficient.