This experience with the Hartford is one of the worst things I’ve ever had to deal with

So I was out of work from 10/23/18 through 1/7/19 because of some mental issues. I was paid up until the end of November and then I was released to go back to work on 1/7/19. Since then, they have denied my claim for the month of December through the 7th of January. I opened the claim back up, sent them all the paperwork they have asked for, but it’s never good enough. Every time I send what is requested, they come back and request more. This has been going on for almost 5 months now and I feel I’m losing my mind. All I wanted was my last check which I should be entitled to, but now I want more. I’ve had to borrow out of my 401k to help with bills and all the interest I’ve lost because of that and not to mention what they have put my mind through. Not a good thing to have to deal with especially when I had to miss work for an already mentally challenged mind state. This experience with the Hartford is one of the worst things I’ve ever had to deal with. I would really like to know if I took them to court what my chances of receiving more compensation than just my last check.