Virgin Mobile/IPhone Help!

So I’ve had the same number for about 3 years now and I recently changed it but now my IPhone wont receive some of my messages! It still has the old phone number programmed onto it and I’ve tried everything even called Virgin Mobile for help and I did what they said but it’s still the same I just want to get rid of the old number and have my new one on there 🤦🏻‍♀️ I tried switching on and off FaceTime and messages and nothing 🤦🏻‍♀️