Complaint Review: IDC SERVCO

I have just received an invoice from IDCSERVCO for a quantity of 2 toners.  The amount due is 781.76  I spoke to a very, very rude lady name Stephanie and told her this order was a mistake and I need information on returning the product.  My intuition had already prepared me to choose my words carefully and maintain a professional audible tone.  She was very relunctant to provide the information that I had requested but nevertheless she did.  She had even faxed me a signed copy of my signature on an fax confirmation sheet.  I admit that I do remember signing this form but when I did this I was led to believe I was dealing with my local vender who I usually deal with.  They had posed as my local company and tricked me into sigining a fax confirmation.  I asked this lady to fax me back a copy of the order confirmation and I noticed that my printed name was forged and the order was doubled for 2 Toners for the redicolous price of 781.76.   I also told her that we don not need ink from them because we are already under contract and our Toner is free.  I even remember when they called the first time and they lady asked me what type of printer I have and I immediately told her in my response that WE ALREADY HAVE A VENDOR.....after I said that, she HUNG UP in my face. No goodbyes or thank you.