My surgery was denied but now the surgical coordinator said that they just need a letter re-written. I asked if it is then approved and she said "Probably but who knows?" I am scheduled for pre-surgery work up tomorrow (blood work, etc) for surgery scheduled on the 10th of november. Should I still do it? I am already doing the liquid diet which I don't mind but I don't want to pay for the pre surgery stuff. I mean, if they deny me, in the end, wouldn't I have to pay for it?

Yeah, don't do it. In my experience, you need to have all the pre-authorizations in place, or they may very well not pay. All you need is to have a big bill at the doctor's or hospital that you plan to use for your surgery all upset that they haven't gotten paid. Unless you pay for it first, then you may have a hard time getting reimbursement. Keep trying, because it really is worth the wait. I worked on this with my insurance company for almost a year. Good luck!