Impossible to cancel or reschedule

I have a booking with this establishment and I’ve been in contact with them since last week to cancel or reschedule my booking for the 28th to the 30th of December. They are making it near impossible to do any of the above after I’ve explained I’ve been in and out of hospital and I’m unable to travel. I need this resolved ASAP I’m in no position to lose a lot of money cause of greed.