Try to make professional-looking Wikipedia page, buy few article mentions so your name will rank up higher in Google. Make fan accounts, meme accounts… boost it up to like 500 followers with just reposting.
And constantly send requests. It will get resolved.
My theory about verification is that it is completely manual (that is, an operator of Facebook-Instagram assigns it by hand) and the first thing it does is to do a Google search to see if you really are a famous person.
Here in my company we managed several celebrity accounts, some of them were verified and others were not.
Of the 3 that were not verified, one of them was in the most known program of Argentine television in the last year. Therefore in Google there were many pages talking about that person.
At that time, we tried the verification again and they gave it to him.
Therefore I believe that the first thing they do is see the results in Google.
SHORT STORY: Make them famous on other platforms first.
LONG STORY:
Get them verified on Twitter first, it’s a loteasier there
Create their Wikipedia pages or get them up to date
Create their IMBD pages too if they’re models & actors
Develop their personal websites as well
Sign up for Help A Reporter Out and get your clients’ quotes in as many print and traditional media as possible
Help them create and produce epic viral content
THEN once you’ve done all of this - request it again.
And since they’re willing to pay a lot for it, bill them to help them set up all that I mentioned above. All of this work is easily worth and billable for thousands. You could even build out an agency dedicated to doing just these things alone.