Wrong address on tax certificate, impossible to update address.

I have been with discovery now for ten years. In this time I have lived in 4 different houses. Every time I move I update my address on their online portal. For some reason every year when I get the tax certificate from discovery, it still has my original address from 10 years ago. I also called them and they have my new address on their system. But the tax certificate always comes back with my ancient address. How is this possible? Thing is, SARS does not like this very much. Please help.