i found a way to fix that.
just get a whatever sim card, not your current one and put it to your device and active it.
so disable the imessage again.
next time it will work for you.
don't pay them money.
This is probably the best solution even Apple should have suggested something.
Anyway, thank you very much. This solve my problem.
I actually tried this though and it's still trying to send as iMessage even to my iPhone with it just disabled. It's so frustrating.
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