iMessage & FaceTime on Mac and iPad

Then what did your phone carrier or Apple support say when you contacting them about the issue as outline in the link?

Still not activated after a day?

It might take up to 24 hours to activate iMessage and FaceTime. If the issue continues after 24 hours, follow these steps:

1. Make sure that your device has the latest version of iOS.
2. If you're using an iPhone, contact your carrier to make sure that you can receive SMS messages.
3. Contact Apple Support.

Make sure you tried everything outline in this link If you get an error when trying to activate iMessage or FaceTime - Apple Support