Pull the other one, stating that his bank knows nothing about it? The charge back will register on your actual bank statement and within the last couple of days not the paypal screenshot you have shown that shows the single payment........ You cant duck and dive out of this one.
And yes, the bank/credit provider does and will provide a transcript of the charge back statement, you'd of had one in the post and email conformation too. The details you needed to fill in is lengthily and not done on the fly.
Already done, what he has attempted to do is file the charge back through the bank. That then triggers the dispute via Ebay, you get the option of providing a tracking number as evidence or (what he hopped you'd click) refund the amount. So essentially deceiving you into voluntarily making a refund payment and not really checking. Cheap but crafty, I wonder how many people he has conned through that alone.