Heartless Supplier

My sister Nokuthukla Madi was suppose to get married to Themba Zungu on the 28th of March 2015, now the groom passed on the 9th of March 2015. They shoot him in cold blood, we buried him on the 14th of March 2015. This is a tragic situation that we both families never saw coming. However, my sister informed the venue owner of her situation, but she refuses to refund and understand there can no longer be a wedding, because the groom to be has passed away. We feel that she's been insensitive and heartless to refuse a refund to my sister. She's claims my sister signed a contract that stipulates that, if somethingm like this happens she will not be refunded. Please help us Peter