What I make of that is 5 + 2 = 7, which of course surprises no one.
How about just stating what you think is wrong about the post rather than trying to be subtle and hinting at something nefarious while pointing out basic facts.
"Last year Abe said he was 15 years old, now he claims to be 16! Which is it Abe? Better keep your stories straight."
Why?
Well, he said so two years ago, after working with them for 5.
Then what? He opened a new account or got his old one resurrected? We have no idea.
What we do know is that now, 2 years later, he's posting the same story on Trustpilot but now claiming 7 years of working for them.
I'm not saying my interpretation is right but you have to admit that this does seem a bit fishy.