Never try to change your address with Vodacom, it just can’t be done - apparently

How can it be so difficult for a large company like this to not be able to change a client address and surname? I have tried and failed to do this for the past 6 YEARS. I have been to stores, told to phone Vodacom. Phoned Vodacom, told to email cusromer service. Emailed them and got an automated response asking for copy of id etc. Sent all the required info only to time and again receive automated replies asking for the same info again! What more can I possibly do to get this done?