Unsolicited call from rude call center agent

Received an unsolicited call from an extremely rude call center agent. They alleged that I had received a sms informing me that I would receive a call - this is untrue. They could not tell me where they acquired my details from, in contravention of the POPI act.

The person started raising their voice to me and called me rude numerous times. I lodged a complaint with their customer care after the incident on the 24th of November 2018 and have since followed up, there has been no response.