When are you going to change my res address???

I changed my residential address at Sandton City more than 5 months ago and provided the required municipal account. I have been receiving statements with an outdated address and I have queried this with them a month ago and they promised it has been fixed and I will receive statements with correct address. Last week and today I received statements again in an old address.. How long does it take to update my address after submitting utility bill 5 months ago and sending an e-mail to advise of this error. What happens then if I cancel the e-mail statement and revert back to an address, is my statement and confidential transactions going to be received by other people. Standard Bank get my records right I even have a reference number for the e-mail I sent which is ***, this is getting so annoying now!!! I really don't see myself following up on this again