Cannot Deactivate My iMessage Account

Hello,

I recently got a new phone - HTC One and I am unable to deactivate my iMessage account - therefore when people try sending my text messages, they are not coming through because iPhones try and send me iMessages. Since I dropped my iPhone in a sink, the screen does not work so I cannot sign out of iMessage that way. Also, when I go to https://supportprofile.apple.com/ to deregister my iPhone that way, there are no products to deregister. Please help!