Telkom Attorneys... Phising???

This company keeps phoning me on behalf of Telkom and then requesting my date of birth before we proceed with the call. I have no idea why they are calling as I closed both Telkom accounts in 2017 and 2018 and they were settled in full.

When I refuse to provide my date of birth until I know what the call is in connection with the lady got quite aggressive and threatened to keep calling me. I will not hand over any personal information without understanding why you are calling me.