I have never tried to get a new number but does it go by zip code or area code? Zip codes are a five digit code for mailing items, area codes are typically three digit. Depending on what it is asking for, maybe you are entering the wrong number zip instead of area?
Good feedback, I was hesitant in suggesting reaching out to support in my response, because that is my typical response in these help needed forums. I am going to get a reputation of just posting 'reach out to support' and that is not at all my intent.
Glad you tried it and it worked out.