Bad, slow service :(

I've submitted documents to have my address changed on 23 Dec 2024, after the Hercules branch gave me the run around with their bad service. On the same day I received an email stating my documents are fine and I don't have to do anything else, but my address has still not been changed. It's almost a month later, and my address is the same as previously. I'm definitely not going back to the branch again to have this changed, so how long does it take to change an address?