Threatening emails

I have been receiving threatening mails from Lifestyle legal (Pty)Ltd demands I pay them R1275.53 They did not render any service to me, I have no written agreement, I did not sign anything, and then they went and obtained my personal details without my permission and have now they are threatening to send me a court summons to pay this amount.Surely the court should look at if this is legal. How can some random person demand this money from me and I have never had anything to do with them.