Apria Healthcare is asking me to pay for a maintainance fee that I never purchased Indianapolis , Indiana

My son needed a Compressor Nebulizer System. My insurance leased to buy the system. According to the agreement, we paid monthly payments for nine months and in November of 2008, we made our last payment for that machine. I was told that the machine is ours by both my insurance company and Apria.

Six months later, I received a bill from Apria in late May, 2009. I called my insurance and they told me that it is probably an insurance (since I paid for the machine) and I do not need to pay for that since I did not purchase it. I received another bill from Apria in December, 2009 . I went to Apria office and they told me that this is a maintenance fee and they will stop it but I need to pay for last year. I told them that I never purchased that and they threatened me with collection. I called Apria FOUR times and each time they gave me hard timeand at the end of each call, they promissed to investigate and call me back. They never did!!!!!!!!!!