Bunch of ****s

On the 12th I got an SMS from P&P Attorneys informing me that my account was handed over to them for an outstanding Telkom account. Today, 15 September, 3 days later I get a threatening SMS stating that I will be blacklisted if I do not pay the account by 3PM today. I have no proof from Telkom stating that account is handed over and the amount owed is less than R 600. I also have no statement to prove their claim. Being threatened with legal steps and blacklisting is low - a bunch of ****s. No email was sent and no other communication.