THIS IS A LAST RESORT PROCESS, IT IS GENERALLY NOT NEEDED AND CAN SLOW DOWN RESOLUTIONS
If a phone number is being blocked or has other issues where Twilio has guided to remove and re-assign a phone number to a client/campaign, the following steps need to be followed from the Twilio support console. If you do not have access, escalate to Rex or Joel.
1) Find the messaging service by going here and searching for the Message Service SID:
https://console.twilio.com/us1/develop/sms/services?frameUrl=/console/sms/services
2) Go to Sender Pool
3) Make sure you've got the number copied
4) Delete the number
5) Find and add it back again