compartment syndrome

I had extensive back and neck surgery in June. Eleven hours on my stomach. The IV in my left hand was apparently never checked. In recovery, my left arm was as big as my leg. Arm was treated while in recovery
from the surgery. The swelling went down in about a month. Four months out. I have nerve damage in my fingers, and chronic pain and weakness in my left arm. The surgeon did a fine job. But, someone did not. Where do I go from here?