I can't delete old phpne number and add the new number for iMesagge or FaceTime.

Try --> Add or remove your phone number in Messages or FaceTime ...

An extract from the above link....

Remove your phone number

If you don't want calls or messages for your iPhone on your iPad, iPod touch or Mac, you can remove your phone number. There are two ways to do this:

• On your iPhone, go to Settings > Messages > Send & Receive. Select your Apple ID and tap Sign Out. Then go to Settings > FaceTime, select your Apple ID and tap Sign Out.
• If the phone number that you want to remove belongs to an iPhone that you can't access, change your Apple ID password.This removes all phone numbers from your iPad, iPod touch and Mac. Calls or messages for the removed numbers won't appear on those devices anymore. 

If you have questions, contact Apple Support.

1. Go to Settings > Messages and turn off iMessage.
2. Go to Settings > FaceTime and turn off FaceTime.
3. Restart your device.

Remove the temporary number from https://appleid.apple.com

Watch the GIF below

1. Turn iMessage and FaceTime back on. (Watch the GIF below)