"Surgery cancellation twice"

I was booked in for an operation but this was cancelled as the consultant said I needed to go to whiston hospital instead of st helens due to my COPD.

New appt pretty quick. The day before I had a phone call to say it was cancelled due to an emergency cancer patient. And that the whole day list cancelled.

I work and twice now have had to book holidays to cover the days off. And now again. Frustrated. They have advised December for the next date but have also said that is not definite that it won't be cancelled again. I find that ridiculous.  

I could keep going on list and taken off if they get emergency. I have COPD; I am trying to get the op done before I catch an infection as I usually do in the winter months. If that happens, I'm told I would not have the op and would have to be taken off the waiting  list until I'm better. Which means going all the way back to start. I have been waiting now since July. What can I do?