Unfairly treated,need a refund

I booked for cruise and fully paid mmy booking by the 2nd Nov 2016 and unfortunately on the 19th of Nov 2016 there was a boat accident and people lost their lives.lives . I sent an email to online boat cruise to ask if it's possible to cancel and what would be implications but the next thing they told me that iI've cancelled.cancelled.Fortunatelcancelled cancelled.Fortunatelt for me it was an email so I told him to re read my email and ask them where does it say cancel and the next thing I was advised that they have already booked a larger group than mine on the same day we were booked, they will ask them if they will like to reschedule . This really surprised me because I booked and paid by 02 nd of November already and this group only booked on 28th Nov,5 days before the cruise but they are given 1st preference . The company called me and advised that that group refused to reschedule so I can take an open booking on Sunday the 4th Dec 2016. I advised them that I was not available for that day and also other people that I was cruising with were also not available . I declined their proposed day. I left the matter for January and they kept on telling me that they will look into my matter. I escalated this matter to their board after sering that this conpany is not willing to help me but even there was also not helped they advised me that online boat cruise gave me an alternative date and I refused to take it.Please help,I paid them R6420.00for that cruise.cruise . Another thing I've tried to aask them their business address they do not want to give it to me.