when you created your apple id? what was the region that you have chosen?
Is there a number i can call? I can only find live chat
PH 125 8881
* I am a Boost Australia customer. This is a peer to peer community where users help each other.
these thread might help you out;
I had this exact same problem after porting my old number over from Telstra to Boost. It just wouldn't recognise my old number as an iMessage option, even though I could make and receive calls and texts from it. I eventually solved it after an hour on the phone with Apple support. The problem seemed to be that my old number was showing on Apple's systems but it hadn't synced with my iPhone. After trying a few different fixes which didn't work they finally asked me to 'Reset all content and settings' - and lo and behold that fixed it. Phew!!!