How to cancel a uncleared echeque paypal payment?

Hi, last night I made a payment to a ebay seller through paypal with echeque, however I have a change of heart and I want to cancel the payment. How do I begin to do so? I contacted the ebay seller asking the seller to cancel my payment and telling the seller my paypal seller, but if that doesn't work .. is there anything else I can do?

Should I contact paypal?

I don't see a option for cancelling the payment myself which kinda sucks.

Please and thank you.