Harassment from Vodacom

Each and every single day I get a phone call from ***. This is Vodacom trying to sell me life cover. EACH AND EVERY DAY I say NO - DO NOT CALL ME AGAIN. Now I have had enough. I tried calling complaint center... no they don't have one... ok so let me speak to a manager - nope sorry they all in a meeting. Now.... one more harassing phone call and I WILL CANCEL with Vodacom!!!!! It is the most irritating thing on this earth! Harass me one more time!!!!I have had enough now!