Unrecognized trusted number

Somehow I got locked out of my iCloud and now when I try to login it takes my password but ask me for a trusted number I never put in a trusted number on the account I never had to sign in that way however the last two digits of the trust that number is five for the last two digits of my phone number is 72 and has been for the last six years so I don’t know what number they are talking about but now I can’t receive messages on my phone from people who have iPhones and customer service do not answer the phone what can I do please help