Zynex Medical "Over bills for its products" Lone Tree, Colorado

Zynex is one of many reasons why health care costs so expensive.  The company over bills insurance companies a ridiculous amount of money for their products.  I received a TrueWave TENS Unit post-op, a knee surgery back in 2010.  Zynex billed my insurance company $278 MONTHLY for rental of the equipment and $170 MONTHLY for supplies (which included:  5 - 9 volt batteries and 5 - sets of electrodes) for over 6 months.  My insurance company paid the entire amount in full with no issues.  I have recently started working in the medical field and part of my job involves billing. Come to find out that the TrueWave product is approximately cost (on a high end product) $200, electrodes are $6-8 and batteries $10-15.

Early this year, I was contacted by a representative of Zynex requesting I return the product and forward the last insurance payment to Zynex directly.  I explained that I had forwarded the most recent payment from my insurance company and then questioned her at what point do I own the product since my insurance company paid (by this point around $3,800) for all these products. 

She stated I owned the TrueWave TENS Unit at that point and that my account was closed. 

It is now 12/2012 and they are still trying to bill me for a remainder of $400, they claim I owe, for a machine that is worth $200 and they have already profited significantly from (total amount insurance paid for everything $3,800).