Hey, I don't know who you've talked to with Apple Support, but I use to be a Senior Advisor for Apple iOS Tech Support. I dealt with your issue alot being a Senior Advisor. Right before I left in November, Apple made this problem, so much easier to fix. I can assure you, that so long as you all Apple Support, ask to speak with a senior advisor, inform them that you use to have an iphone and now you have an android phone and aren't getting your text messages, they will be able to help you out. You will also have to be able to verify your Apple ID account.