If I have an issue with my chain (company level) and my battalion COC isn’t taking action what should I do?

Based on what I just read....You tried going thru your Chain. That didn't work. Your 1SG basically told you that you won't be going to the BN CSM. Well....that's a NO GO. No one can stop you from using the Open Door Policy of your higher commands. As long as you tried at the lowest level first and nothing worked/fixed....then walk into your BN and ask to speak with the CSM on the grounds of Open Door Policy. Have your ducks in a row first. As long as you tried everything, got your ducks in a row....watch how fast CSM gets things rolling

I suggest that you try to get consideration starting at the lowest level. Many leaders will get pissed if a soldier jumps over their heads.

Any PL or PSG worth their salt would back you. Surprised someone has not offered to help. PL has trust of CO and has leeway with taking care of his people. Same with PSG and his seniors, or they should at least. Big difference between missing and accounted for on morning report. This would be Sergeant territory in USMC, or even Corporal. They'd go to their SNCOIC or PSG and explain, who would grant the day off with instructions for a working party to be exempt from PT to help you. He would inform PL, as a courtesy. After that he'd expect a report from you or the chain on your status by COB.