If you entered the wrong code x3 times then you can no longer confirm your bank account that way.
It takes 4-6 days for the code to show on your bank account statement so guess you didn't bother to wait? You would need to wait until the phones are up and running again and then ask customer services to add it for you. They would probably request that you upload a copy of your bank statement to prove ownership of the bank account as you couldn't manage the code method.
Advice is voluntary. Kudos / Solution appreciated.