3 months, no offer letter. Will bank statements be enough as proof of employment ?

Prior to joining here, I had around 1.5 YOE. This is an EdTech company (government exam sector). During the interview, I thought I would be working on their app and website. But after joining, I got to know that everything is outsourced. I was mainly handling CMS (content upload/update) and a few small internal portals.

Here I came across the most inhuman person I have ever seen. He is the main guy who manages everything. He expects people to work from 7 AM to 11 PM, with no day off (not even sunday). Even after doing that, it is still not enough for him, and he fires anyone at any time. He himself once said that because of the bad job market and people's compulsion, they can easily hire people for 15-20k. I mean this is their core hiring strategy.

My first month was an internship, and I received the internship letter then. But now it has been 3 months, and they are still not giving me the Offer Letter. At this point, I don't even know if this organization is properly registered or not. For context it has subscribers in million & over 10 Lakh students on their app.

One thing is that they opened a salary account, and every month my salary gets credited with the organization's name in the bank statement.

My question is, will salary credits, bank statements be enough for future companies if I explain this whole situation honestly? Has anyone been in a similar situation?

Right now, I just want to get out and find another company. I don't know whether it will take 2 months, 6 months, or even longer, so for now I'm stuck here.