I cant get my confirmation code for security check

im not good at explaning but here i go. Facebook is asking me for a confirmation code to confirm my identity and this is the 2nd time the 1st time i had a working phone number so i entered that phone number but the phone doesn't get messages and phone calls anymore and Facebook says i cant change the phone number and thats a problem because if i cant change the phone number i cant get in my facebook account and it says i cant get the confirmation code with email and i tried making a new profile but it doesnt acept my request to make it.