I've never worked with people that are so obviously stalling before. Bunch of crooks

I have been disabled for over 10 weeks and Principle kept saying the forms incomplete so they needed all the medical records from my doctor, including office notes. After many calls and explanations I was told I was all set. But alas, I hear nothing from Principle for several days so I call and find out my case was transferred to another agent. Now I am being told that I need to provide all the doctors I have seen over the past 5 years and they will need to send all their records to Principal and I must prove that I have become disabled after the policy started on January 1, and not before, even though my physician who is overseeing the entirety of my health has already provided a date that proves I am covered. I have never felt like I was dealing with a bunch of crooks and con artists this bad before. I have never worked with a company, or people that are so obviously stalling before.