Complaint Review: Pendrick Captial Partners II LLC

I recieved a bill for $1,188 dollars from a collection agency called Transworld Systems Inc. They said that the creditor is Pendrick Capital Partners II LLC. I called the hospital the bill states that I recieved the care and was told that my insurance covered it. The bill states that my insurance was terminated and that it was sent to collections because they couldn't get ahold of the payor. I called Transworld Systems and talked with a manager and told her of this and they still insist that I owe that money. I asked for the phone number for Pendrick Capital and she said that I would have to find that on my own. I did find that on my own and called and the guy that answered said hello and I told him my name and what the call was about. He said I would have to call customer service and gave me the number. I called them and no answer at all. I am really upset because they have my insurance information and my social security number but will not take care of said debt that was already paid for by my insurance company.