Can't send & recieve iMessage with my phone number

hi,

I'm using iPhone 4s with iOS 6.0.1

The problem is I can't send & recieve iMessage with my phone number. The activation always unsuccesful 😟 Using iMessage with Apple ID is OK.

The phone number displayed in "Phone" is correct (+84989892289)

I did many solutions which posted on this community but they didn't work (reset network settings, reset all settings, clear all data and settings, full restore firmware ...)

I used some my friend's simcards with my iPhone (4s) and they worked 😐

I used my sim card on my friend's iPhones (4s, 4 or 3GS with many versions of iOS) and it didn't work 😢

I asked my cellular provider to change another micro sim for me and it didn't work too 😮

So the problem is about my phone number?

Please help me and sorry about my bad English.

Thanks so much

Regards,

Anh Tran.