First Report the seller to eBay as a non-performing seller.
Now. Did you offer to pay by money order or did the seller demand it? If it was him, did he do so through eBay messaging? Sellers are not allowed to ask for any non-electronic form of payment, although buyers can offer. Your experience is why.
EBay cannot help you recover the payment and you cannot prove to them that you made any payment.
You can leave feedback. The most efficient fb is calm and factual. "Demanded money order. Refused to ship" would cover it, if those are the facts.
You can also leave Detailed Seller Ratings. The lowest Rating is ONE. Sellers whose DSRs drop below 4.3 have their ability to list and to sell severely restricted.
A couple of questions. Does the seller even ship to Canada at all? If not he has the right to refuse the sale. (He doesn't have the right to keep the money though.)
And given the seller's name, can the purchase legally be imported into Canada? You'd be surprised at what cannot,including paintball supplies and fireworks.
