Door bell corroding

I’ve had my door bell for about 18-20 months and it’s literally corroding the outside of it is turning green and the stickers on the buttons have come away is there a way to replace the face plate on a 2nd generation doorbell as I’m really disappointed with the quality, I clean it every time I charge it and every few weeks. It’s designed to be outside it’s under a porch it’s all just really annoying ! Any help on what to do with it?