Vodacom has Zero care of customers!

My Fiance's phone was ****** out of her hand, and we were trying to cancel it through vodacom customer care and it show NO WHERE or any option to block or cancel mobile number, then we went to the grove mall vodacom shop to try to cancel and again they cant help because they we dont have the serial number of the phone because it was ******, my fiance sitting there upset that everything was on her phone and Vodacom being the "the best service provider" couldnt even assist then and there. i am very unhappy that they cant even help in worst situations.