If I had release the payment because of the pressure of customer service in the exchange, the money wouldn't have gotten to me, which the buyer will be nowhere to find to make complains to his bank . Beginners should never make mistakes to release no matter how long it takes for them to receive payment. Hold on till everything is settled from both sides.
I think every exchange has a way of tracking a failed transaction on P2P. That's why exchanges discourage paying to a third party account so it can be very easy to trace in case anything goes awry. Besides, every merchant has a guaranteed deposit they make before they are authenticated. In the same light, there are warning posts littered on P2P platforms that sellers shouldn't release coins to buyers until they're certain the claimed payment has reflected in their account balance. No one should rely on SMS alert for bank transactions. I always take my time to crosscheck and if I don't get the cash in my account, I don't release coins. I don't allow emotions becloud my sense of judgment to the point of hastily releasing coins. Just of recent, I had a similar experience as yours. The buyer claimed he sent my money but I refused to release the coin. Within minutes, the buyer cancelled the deal. Once you're dealing with anyone online and they're trying to pressure you to part with something, know it's a scam.