Sorry you had a bad experience, many others, myself included, haven't had a bad experience.
When I ordered my Chinese battery from Ebay, due to the shortage of OEM batteries, I got a communication from the vendor saying sorry but their batteries would not charge in the Olympus charger, but did I want a free wall charger? So I said yes, they all arrived and work brilliantly. The battery life is every bit as good as the OEM battery, and the charge indicator works as normal, and the camera hasn't exploded.
Did you read what I wrote? Or wasn't it clear? I asked this supplier if the batteries would charge in the Olympus charger. They replied that they would - in perfectly grammatical English. So I bought them. There was no misunderstanding, there was misrepresentation. Let's call it what it is - a lie.
I have no particular problem buying batteries that require a (supplied) separate charger. I'd prefer to use the existing charger I have rather than carry two chargers. Now I have two batteries that won't charge unless I put them in a powered-up car.
As I said I have never had a problem with the four third party Nikon En El3e batteries I've had for the last couple of years. With luck I've managed to prevent some people buying this crooked supplier's batteries under a false prospectus.
Olympus can't even supply batteries at the gouging rate they are charging, so the fault ultimately reverts to Olympus I guess.