Lack of customer service

I have been trying to get a settlement quote from fonechoice, but was told my file was handed to MBD .I then called MBD they said my file was not with them. When I call fonechoice for records they say they don't have .how do I get rid of this debt when it's only appearing on my credit bureau not with Fonechoice nor MBD? My emai address is in my account profile as well as my contact number.