Healthmedica.ca

Hi guys! PayPal is VERY vulnarable for fraud! My story: I posted an ad on Kijiji that I am selling a wedding dress. I got contacted by a buyer who offered to pay via PayPal. I received an email from *******@PayPal.com with transaction ID, that the buyer sent the money but (now I copy/paste):

Important Note: This PayPal® payment has been deducted from the buyer's account and has been "APPROVED"but will not be credited to your account until the shipment reference/tracking number is sent to us for verification in order to secure both the buyer and the seller.
Below are the necessary information requested before your account will be credited. You are required to ship the item and email We at PayPal the tracking number through this mail
*******@mail.com and our customer care service will attend to you instantly. As soon as you email us the shipment's tracking number for security purpose and the safety of the both the buyer and the seller, the money will be credited to your account immediately.
**PLEASE NOTE**
Once the item has been shipped and the tracking number is sent to us for verification, you will receive a "CONFIRMATION EMAIL" from PayPal® Team informing you that the Fund has been credited to your account.
Thank you for using PayPal!
The PayPal Team
VisaMasterCardDiscover

PayPal customer service advised to call Canada Post and stop the shippment. Canada Post said, once it's out, they can't stop it. So now I am left without the dress and without money.

Where is my fault here?!