Unwanted sales calls from Vodacom / third parties???

I am totally livid :(

I have/am receiving several calls on my Vodacom number from companies pretending to be Vodacom / claiming to be from Vodacom for months now. Apparently "Vodacom" gave them permission to contact me regarding my expired contract???

I DO NOT CONDONE VODACOM SHARING ANY OF MY PRIVATE CONTACT DETAILS for any unsolicited / marketing purposes. The fact that third parties have details about my Vodacom account is very concerning to me! This seems directly related to my recent usage of the Vodacom Mobile App or my recent communication to Chatz Cellular at Robertson, Western Cape.

Please PROVE to me WHERE I gave consent to be harassed by sales calls during work hours and thereafter.

This has to stop!