did you check whether your insurance had deductables?

It is your responsibility to figure out your insurance terms and coverage. Most insurance does have deductable. What you need to do is (1) find the documentation that shows that your CIGNA coverage for 2009 did not have any deductable; or (2) show that you have already paid deductable that year on another medical procedure. Otherwise you have nothing to sue anybody for. If you don't want to pay, you need to negotiate with the collection agency and see if they are willing to give you a discount on the bill.