I'm not really sure what the author expected. If you're in KYC and ask to speak to a manager when your document gets rejected, you're going to have a bad time. The person processing your documents can't give you leeway even if they wanted to, they have legal requirements and a process they must follow.
So what do you do when the process has a problem? The document that your country issues that is valid and meets the KYC legal requirement but has a title that the internal process rejects? You need to speak to someone who can say "this meets the legal requirement but our process is bunk"
That makes sense if you're trying to use a costco membership card to board an international flight, but nitpicking over telecommunications "bill" vs "invoice" seems exactly the type of ambiguity that's worth escalating over?