Vodacom - telemarketing complaint

The following number: ********** , which is (according to research) supposedly a Durban based call centre, phoned today during work hours and after finally answering the phone the telemarketer on the line did not even have the decency to introduce where he was calling from. He demanded personal information without clarifying his purpose. Furthermore upon asking the man who he was and where he was calling from he responded rudely and then hung up. This number has been a nuisance at all times of the day and night and this has begun to frustrate my entire family. This is not the way a professional company should conduct themselves and I am appalled. I am currently a customer of vodacom but won't be for long as this is unnacceptable.