Can I sue?

I delivered my baby may 23, my doctor sent in the disability papers to the insurance on may 30. Its been 7 weeks since i delivered and I have not recieved any check from disability. A case hadnt even been open until this weekend. I called them so many times and every time they told me something different. They said they never recieved the papers from the doctor(she faxed them over 2 times, may 30 and again on july 3)then they told me that i would get the checks in the mail within a week and after not receiving anything I called again and they said they didnt even have a case open for me. Up until today(7 weeks later) they havent figured things out yet. Im back at work already and still nothing. 😡 Can I sue them if they dont figure things out?