BAD DEBT BOOK SOLD TO ATTORNEYS WITH ******* INFO

I am being harassed by MBD Attorneys for a debt that they purchased from Altech Autopage. I have tried over the past few years to get a detailed statement of how and when the debt occurred as I have all my bank statements and Altech statements from the start of my contract and have NO outstanding payments one staff member at Autopage confirmed verbally that it is not my debt and will get it sorted, however to date the attorneys still have my information and continue to harass me. I have dealt with Altech Autopage's legal department, both telephonically and sent numerous e-mails and have even sent an e-mail to the CEO B Chislett, no response. My last phone call on 9 March 2015 with a promise of a maximum of 24hr response. I am still waiting. By the way I still have my contract with Autopage So where do I go from here. Legal to get them to respond ??