Parcel delivered to wrong address / lost

[nordic_studio]

Hello!
I'm in Canada. Sold item to US. Shipped by Expedited parcel . Now tracking ( on both sites :Canada Post and USPS) shows that item was delivered to the same zip code as the buyer's zip code. Today customer reaches out saying that the package had not been received. Buyer opened case with eBay - claims she did not received the item and asking for a full return. She said that she called to the post office and was told : parcel was delivered to the wrong address and that she may not get it because the mail carrier may not be able to get it back. People in the wrong house deny it. 
I did ship this parcel by EXPEDITED International parcel. Which means that receiver must sign on delivery. But she said that postal office manager told her that this parcel sent with a tracking number only, not a signature.
It wasn't my fault. I double check shipping details, sent her copy of shipping label and receipt What can i do?

[momcqueen]

If this was one of your fur coats for $300 CAD, you were safe to have used Expedited USA Parcel without signature.

If it was the one valued at $1000+ and you used Expedited Parcel USA instead of Xpresspost USA, you are in some trouble right now, I'm sorry to say. You will pretty much have to refund upfront and then chase the post offices to admit they left it at the wrong address. 

Within Canada, you can add a Signature to Expedited Parcel for a surcharge but when you're dealing with a cross-border mailing, it's Xpresspost or nothing. No other service allows it. Again, the threshold for paypal is $825 Cad the last time I looked. 

Like I said on my other reply, you'd be wise to call ebay and learn your full rights and responsibility with this case.