Help save my kitty's life - He needs surgery!

My kitty has been at the emergency vet hospital since last Wednesday. We knew he needed surgery on Friday, however, the vet does not have a surgeon operating on weekends despite being a 24/7 hospital. They initially told me Monday, but that didn't happen either. They are charging me to keep him there and they will not budge on cost. I can pay for the surgery, or I can pay for them to just sit and hold him at the hospital until they have time to do his surgery, but I cannot pay for both. As it stands, I am on the hook for 4k more than my deposit was for the initial "full surgery and treatment" cost, and I don't know how I am going to pay that. Anything would help us hold out - He's a young cat, and healthy, and has an amazing chance at a good life post-surgery... I just need help to get him there.