Right, so after reading about 50 threads on fixing the activation problem, I still haven't found a solution. iMessages worked fine until I shut down my iPhone today because I was in a meeting and after I turned it back on, iMessages could not activate. It just says that it's waiting for activation and that window does not disappear. I tried resetting network settings, airplane mode, home button+lock button reset, but it won't activate my phone number anymore. Is there a fix that DEFINITELY works?