Empi Inc billing outrageous unfair charges St. Paul, Minnesota

On Dec 5th, 2011 I went to the doctor complainting about low back pain. The doctor recommended to take home an Empi device to help relieve the pain. She sent her assistant with the device who explained me that he checked my insurance and the device was covered so I didn't have to pay anything for it. He opened the box and all the packages inside it, put it together and told me how to use it. He even told me that if I run out of batteries not to ordered through Empi, because there were very expensive, to just go to the store and get regular batteries. I took the device home and never used it, because you need to lay down in bed for 30 minutes and I never found time for that. Two months later I received a bill for $134.18 from Empi. I called inmediately and they said I have to return the item right away if I didn't want to get more charges. I put in the mail the next day. The charges were for the co-payment of the insurance includin usage (rent) and supplies (all the packages that the doctor's assistant opened).The total charges were $263.50 and the insurance paid $129.32 teh rest it was my responsability. I tryed to explain a manager in Empi what happened but they didn't care and send me to a collection agency. My credit score is of 780, I paid of my bills; but this one I'm not willing to pay. It's not fair!