Default listed on my credit record

I contacted transunion yesterday and was sent my most up to date credit report. Today I received a notification from transunion informing me that a default was listed on my credit report by Telkom Mobile. I have NEVER EVER had any contract let alone CONTACT with Telkom. When I checked my credit report yesterday there was not any record of anything related to telkom. You are affecting my credit negatively and I don't know why!!! I want the default removed from my profile or I will take this matter further. I have not once received a call or email from telkom, so where on earth is this default coming from???