Really there are too much fraudsters in the exchange. There was a day I was selling 0.008 worth of BTC in binance and there vendor indicated that has paid the money to my account but I didn't receive any alert of payment but he was disturbing me to release the coins but I refused.
If you choose a trusted with high reputation and with high past trading volume, you will have less probability to trade with a scammer. Because a trusted vendor will not sacrifice his account reputation that is gained after a long time, to scam in one trade.
In addition, scammers always push their trade partners in hurry to release coins. It is one of alarms for a scammer.
I even told him to send me a screenshot of the payment he refused too. With the long argument for about 3 to 5 period he paid the money and I received the alert so I released the coins for him.
When you trade Peer-to-Peer, only release your coin if you receive payment if you are a seller; always mark the trade as Paid if you are a buyer.