The problem here is that the discrepancy is in the favor of the power company. As long as they're making more money and especially because the "Accredited Testing Agency"'s own tests won't detect the fault, it's unlikely anything will be done about it unless there's an obscene amount of media attention paid to it and the regulators step in requiring a correction.
... Though there is one way that might happen more quickly. I wonder if there's a converse effect? Are there methods for consuming electricity on these meters that they similarly fail with but woefully under report the amount of electricity being used? If something like that was discovered and publicized enough for people to take advantage of it, I'd imagine the problem would get fixed on the short order. I'm pretty weak on electrical engineering, so I'm really thinking of this from the perspective of "Hey, that same flaw that allows an attacker to exploit my phone also allows me to gain root and unlock it!"