If I am covered by Guardian STD, why are they telling me to file with the state?

I had surgery on October 10th and they just now closed my claim. She is sending me a check for 20 dollars, I haven't even gotten to talk to her, only customer service. They told me she is relying on the state to pay me my benefits and that she's only giving me the minimum amount they can. She says I was eligible to go back to work on October 23rd when all my dr note said was I have a post operation visit scheduled for October 23rd, and another note from him stating I will return to work on November 15th. They claim they never got the second note and processed to send me 20 dollars for the 5 weeks I've been out, and that's as far as I've gotten; the state of NJ has on their website if I apply through them they'll just forward my paperwork back to the private insurance company. I have no idea what to do.