I recently switched from an iPhone to an Android. I turned off iMessage on the iPhone and tried to deregister it via the webpage but I never got a code. I tried to restart the process by texting STOP to the number but I think that screwed up my chances of being able to deregister it that way. Regardless, I still can't receive texts sent from iPhones.
iPhone 6, iOS 9.2
"I texted STOP in response to a code from the Deregister iMessage webpage. How can I get a code now?
Contact Apple support to deregister iMessage. You won't be able to get a new code from the webpage."
*Above from the deregister FAQ Deregister iMessage: Frequently Asked Questions - Apple Support
Get help if you can’t receive text messages from an iPhone - Apple Support
These steps won't deregister your phone number with iMessage: Texting STOP to 48369
Try texting HELP to 48369 and see if you get a response. This will make sure you are getting short codes. If you continue to not get the code, contact your carrier to ensure short codes are not being blocked at all.
Deregistering iMessage
