Nightmare

I have received emails from the company called computech credit services stating that I am owing them money. The have sent me summons to make payments into their account with different amounts, R1400. 00, R1900. 00 and R1700. 00. When I asked what am I paying for they say is for the service they provided for me when I took a loan. I have never taken or app**** for a loan since in my life. When I call their number is just ring and now I am getting frustrated as I am working for financial institution and these kind of things turns to give negative impression to my employer. Kindly assist as I want to understand what is it that I must pay for as the company itself do not know when or how much loan I app**** for. They cannot provide ved me with proper information as to why I must pay but they keep sending emails.