Payment sent through PayPal f&f echeck

Description

A little background information: I purchased an item from someone online using G&S but then he refunded me the amount. I again sent the money and he refunded me saying he has been "duped" when the buyer has used G&S. I wasn’t aware too much of the difference at the time. I then sent a payment to one his other paypal accounts of the same amount but through F&F expecting it to go through. The payment for some reason was a echeck and I didnt know what this had meant at the time and it’s on pending at the moment. He then asked me to send the money through revolut instead since it hasnt gone through. I sent my money through revolut but after I had, i had soon found out it was a scam and it was too late at this point. The payment I had made on paypal was still pending and so I tried to cancel it but paypal wouldn’t let me and told me to contact the bank. I contacted the bank and they said to block the card and cancel the direct debit to paypal. In this case, if the echeck bounces what would happen? I’ve seen on some posts that paypal would pay it on my behalf which is something I definitely do not want. I have this made this into a dispute but paypal just declined it. I’m not asking for my money back, I’m asking for them not to take my money! I just want the echeck to bounce and leave it at that. Any help is appreciated.