I have a new phone number. For some reason, I'm getting text messages from my old number on the new number. How is that possible? I've also sent text messages from my new number and the recipient sees that it's coming from my old number. Wish I could post a screen shot. 

I am still using the same phone. I just changed the phone number. 

Also, when someone calls the new number, there's no voicemail message but if they call the old number, they hear my greeting.