Been with the USPS almost 30 yrs. I've seen people use the same wrong zips for yrs and not catch it. We still get their mail to them Not saying this is the case here. But really is only an issue if clients stop getting their mail Then they realize they had it wrong in the first place. And it was just a typo on something then it might never be caught.. Sorry your gonna have to do better than this to convince anyone.