First Data

I returned my old credit card machine in May of 2011. I took notice on Aprl 16, 2012 I was being charged by First Data Global Leasing twice a month five days apart for the lease. I called them and they told me I had two leases with them because I did not return the credit card machine. I did return it but I did not have a tracking number for it and they told me if I did not have the tracking number they would not credit my account. They have been charging me $54.86 since JULY of 2011 til present. They told me they would close the lease for $20.41 which they charged my account on April 20, 2012. The bank told me they had the credit card machine and they gave me the date they received it and the serial number to the machine I called First Data with this information and they still told me without a tracking number they would not credit my account. I called my bank and they said it is not in their hands to do anything about this matter. WHAT IS GOING ON HERE! Why didn't the bank return the machine to me if it is such a big deal? The leasing company knows I do not have. it so what is going on here?