The automated ID verification might fail for a variety of reasons (frankly if they don’t originally have a copy I’m not sure what they’d be comparing it to) but the GDPR process should work if you fight long enough. You might need to prove that you owned the email or number though - email might be tricky but number is easier as you can submit a bill or do another subject access request to your provider which should still have records about it.
The automated ID verification might fail for a variety of reasons (frankly if they don’t originally have a copy I’m not sure what they’d be comparing it to) but the GDPR process should work if you fight long enough. You might need to prove that you owned the email or number though - email might be tricky but number is easier as you can submit a bill or do another subject access request to your provider which should still have records about it.
Good luck!