confused and stressed

I wrote a report on hello peter on the 24th of December 2015 explaining my situation about my contract with mtn, on the 29th of December 2015 I got a response from mtn saying everything is sorted and I do not owe mtn anything, but lately I've been getting emails and smses saying I owe R3500 and I need to pay, I called to find out what this was about and they told me that the mtn response was not meant for me it was meant for someone else. what's going on here? I'm job hunting at the moment and this credit record is not doing me any good right now.