This wouldn't be possible, as C&C generates codes so that the package can be properly identified, notifications are sent, and you can identify yourself when you collect from the nominated store. It also requires a specific address that the seller needs to send the package to, which is tied to the store location you select, so you wouldn't be able to say just send it to the Woolies in X suburb, because once they get it, they will not be able to do anything with it.
The only way is to cancel the original order and buy again, which is not something a lot of sellers would be willing to do (especially if they received your payment via PayPal, as none of the fees they were charged for receiving your payment will be refunded, even though you will get a full refund for a cancellation).
