Like the above have said, you need to get Disney to transfer your toon to the account. You can contact Disney by:
Live Chat (Toontown Live Chat is available from 10:00 AM to 2:00 PM, and from 3:00 PM to 6:45 PM -- Pacific Time -- Monday through Friday.)
Telephone:
1-888-332-1626
E-Mail:
toontown@disney.com