Not a bad attempt - just a couple of suggestions
I am really sorry that I have to request a refund of the hotel fee of $500. My brother died suddenly and I have to attend the funeral service. As I am sure you will understand, his death was sudden and this circumstance is totally beyond my control . Therefore, in spite of your hotel's policy that no refund is allowed , I would like to ask that you treat my request as an exception. I would really appreciate it if you could refund my money.