Can an employer make you work even on 26th Jan? ( If not US/Uk based)

I'm working in a startup since a year now. YOE 3years. For 10 months I took WFH, and I took 10 days leaves in the entire year cause of personal reasons (my grandma and grandpa passed) + 2 days diwali+ half day chhath + 1 day Holi and other casual leaves mainly during emergency. I'm working full day on Saturdays too. Non stop 9am-7/8 pm. After I took chhath leave they asked to relocate to HYD. I did. No if/buts. No questions asked. I'm not even getting any employee benefits as such. Pay is meh, meh is an understatement, I'm getting peanuts. No HR. Working directly with the CEO and Director. 1 more employee works at some other company at daytime and only works at night in this company. So they expect me to answer him too after working hours. Btw director has never step foot in office since the day joined. CEO is always on his phone watching cctv cameras. And it's a Fintech startup. Alums of IIT. And it's not like I've been given some crazy ESOP's for building this company along with them. It was all still fine until they asked me to come on 26th Jan too. Now I don't particularly think that someone who wants to work on national holidays shouldn't. I could've gone and worked If I wanted to, but I'm super exhausted, overworked and in pain, that now even 2 days leave feels like a luxury to me. There would be no extra compensation, no compensatory leave, no prior intimation of this extra day that they asked me to come.

I cannot check my phone during offc hours, they've asked to give offc landline no at our homes if any emergency. What kind of fuckers they are? I know I have options to leave the company or file RTI or anything but I want to rant my heart out.