Fell in uncovered hole at work and need advice on what to do.

I work in the oilfield, with one of the three biggest companies around I got called by the lead-mans to look at a job in test pit On my walk to them I stepped in an uncovered hole. The hole was covered by 2-3 inches of murky, blackish water an I stepped into an open hole that should have been closed but since my boss refuses to let me fix it, it stays open when the hole (a drain) is being pumped. I didn't report the incident because at that moment I was angry and I guess my adrenaline was pumping and I didn't feel it. The next day I couldn't even get out of bed. I tried massages and a chiropractor like the leads (who saw me fall) told me I should. Nothing has helped and the pain is still constant. I can't lift or turn my head. Now they won't compensate me for lost time due to the injury, which in my opinion is their negligence. Today I asked if someone could come in for me while I go to the doctor (I'm contract by the way) and they denied me again. Need advice. Don't have a case?