I had some medical service performed several months ago. I see on my insurer 's web site that the insurance company has paid their portion of the bill. I have been waiting for a bill enumerating the service performed and what I owe. Instead I have received a notice from a collection agency that my payment is overdue. When attempting to call the collection agency to explain, they do not answer the telephone. This collection agency is Transworld Systems located in XXXX, PA.