I want to keep my old number

Contact new phone mobile network provider and ask themif they can port your old number to the new phone.

I think you can through the data assistant tool to detect your phone quickly, even your phone is broken, it can be detected quickly.
You just need to choose the files to back up the computer, then connect your new phone on computer, copy the data like contacts to your new phone.

More help:
Transfer Contacts from Android Phone to Computer PC

need to notify tracphone customer service to assist you

You normally can change Phone numbers and phones online but with your problem it might be past that contact customer service at 1-800-867-7183 it works for me 8:00 Am till Midnight
Good luck rickie

If you need further help, reach me via phone at https://www.6ya.com/expert/richard_b70d968cd1a1d293

Does it work on Wired or Bluetooth headset? If so your microphone has a problem or your phone is muted.

Mark
Motorola Support

First, contact your cell phone carrier and ask if they have two identical numbers for you on record, one for your old phone, and one for your new phone ... but with two DIFFERENT IMEI numbers. The old record SHOULD have been purged from their records when you got your new phone. Then contact Facebook Customer Service and explain the problem you're having.

chage the msg centre no.