VIVO,
While the 8.4 version is available to new subscribers, we are working on the update patch for existing subscribers. Version 8.4 is on a different server than the 8.1 version you are using. The update patch will migrate your account, along with your existing contacts and saved conversations to the new 8.4 server. The update patch should be ready in 6-8 weeks. If you don't care about the contacts and saved conversations, we can migrate you manually to the 8.4 server, but you would have to recreate your contacts and you would lose your saved conversations. Let me know what you would like to do.