Progressive business publications Lin Gregory Threatened collection over publications sent but not authorized. Malvern , Pennsylvania

I received a call from Lin Gregory of Inernatinoal Credit Recovery Inc., (ICR) which stated that we verbablly agreed to a susbcription by phone and failed to cancel the subscription.  Advised her to send me an invoice.  The next day 5/02/2011 we received the invoice from ICR showing Progessive Business Publications in Malvern, PA.  The invoice showed #of people receiving copies of each issued:1 and subscription term 12 monmths 24 issues.  She was asked when did we received the subscription and she stated Oct 2010- March 2011.  I asked her how many issues we received she said   twice a month for 5 months.    She could not give me valid information to support this claim.  I also have no record of any emails from this company.  Ms. Gregory kept asking me to pay the item over the phoneor state whether we would pay the bill.  I advised her that I would and gave her a check # to get her off of the phone.  I have no intentions of paying for something just because she said I should.  Lin works for International credit recovery which I believe is in this with Progressive Business Publications.