The reason why i pull out this thread is that, there was this friend of mine who loves to use whatapp as his p2p exchange, what i meant by this is he alway trade his coins on whatapp with an unknown foreigner who claims to have a preferable price tag which i would say is not adverable, i gust many people today have fall victim to this type of scam, it is always adverable for trader's to alway trade their coins on well highly exchange platforms.
This friend of mine was been scammed just because he was ignorant and greedy, most times we see flyers of this black market exchange.
Is your friends unaware of other exchanges where they can swap coins whenever they want? Is it because this was not his first time trading his coin on WhatsApp, or did he fall victim during the first trial? I've always seen groups on Telegram where people sell their coins, but some people get mind sha to believe anyone they meet online and agree to buy or sell, and this is the first time I've heard that they can even exchange coins on WhatsApp.
However, I still don't understand how this WhatsApp trade works, did your friend by mistake send his coin to the buyer and the buyer not pay him? Many people have experienced this on exchange, when they release the coin and the buyer does not pay them. It's possible that your friend's story could be like that. You should at least suggest an exchange for him to trade his coins the next time because this has taught your friend an important lesson.