sometimes these dodgy fellow only pose as TNB staff to offer you these services, that way u can try report also no use since they just borrow/steal the blue jacket
some more u trust them cos u think they r tnb

also regarding the accuracy of the electricity meters, they are all governed and watched by independent bodies like Suruhanjaya Tenaga, and follow weight and measurement Act.
ppl question meter accuracy but do u question the petrol station whether they really give u 1.90/Liter? or is it 0.8L? or how do telco record ur call durations, is it accurate ? or how bout that weight machine at Jusco when u weigh your chicken