July 12 was a Friday. So we are looking at most at three working days.
Was the refund coming from the seller? Send a reminder on Friday, to allow for bank clearance. (It can take up to 10 days for payments to clear the US and Canadian banking systems).
Was the refund coming from Paypal itself? This is common when the seller refuses a refund but PP finds in favour of the buyer during a dispute.
Were you asked to return the product? The refund would not be processed until you can show that the item was returned to the seller, which again can take 10 days or so,