If your back is clear then a word with your chief pilot is in order.
You have tried the polite CRM approach which was brushed aside in the same tone.
The break down of CRM (in the cockpit) is something which requires a report, so your question to the chief pilot is along the lines of ,"This has happened and this was his response when I tried to broach the subject. I don't know whether you would prefer to speak to him in confidence or whether I should write a report. What would you like me to do?"