Wrong Address/Trying change it for 2 years now

I have been trying to change my Vodacom statement address for over 2 years. I have informed the customer service line, I have been to a branches including Canal Walk/N1 City, I have asked again for when we updated the records for TAX and we are now in September and still the address have not been changed correctly!!! When is Vodacom going to do this or must I wait another 5 years? On my billing account it shows im paying for a laptop which have been paid off long time ago but still it is showing Vodacom is billing me for it????