First Data Merchant services keeps charging for credit card processing even after you terminate your contract Nationwide

This company is a credit card processing compnay that my bank used , I terminated my contract over a year ago and was charged almost $300 in fees. they said I had to pay and that then we would be done. I just got another bill from a debt collection agency ( one year later ) sayiing that i owe almost $300 again. 

I can't get any information on what the charge is for.  I am pretty sure the "debt collection agency " is just another branch of their scam to get money out of people for all etrnity.