Had enough of your unwanted spam calls

I receive many unwanted and unsolicited spam phone calls from Vodacom's outbound call centres or third-party institutions performing this function on your behalf trying to sell products on a daily basis. Today I received no less than six calls(!). This is outright harassment. You do not have my permission to contact me in any unsolicited way whatsoever. Please remove my contact details from all your records and those of your service providers within the next seven calendar days and advise me when this was comprehensively completed. Thank you kindly