I don't know why the CSRep thought that it was a bad thing the invoice was for goods. They're so clueless.
The fact that the invoice was for GOODS instead of SERVICES was a step in the right direction, as services aren't covered.
The item you purchase must be a physical, tangible good that can be shipped Source
Purchase Protection does not cover certain kinds of purchases. These include: digital goods (intangible items), services, real estate, motorized vehicles (of any kind), custom made items,Source
In the future, the trick is it needs to be worded such that you're buying a report or a CD with the software, etc. (not the programming/development service from a person). Then you can always file an INR (Item Not Received) or SNAD (Significantly Not As Described) claim if something goes wrong. You need to be proactive in making sure the invoices are worded to your advantage.
However, even if you had done that, multiple payments are generally not covered by the PayPal's Buyer Protection policy. Source - it's off the US PP site, but I think they're similar across the board on this issue. You can check the Canadian PP Buyer Protection policy.
What are the eligibility requirements for PayPal Buyer Protection?
You must meet all of these requirements:
So, sorry, not good news. I think you're out of luck. Unless, maybe you funded the payment with a credit card and can try to do a charge back. But the general consensus is that PP hates charge backs, and might limit, or even suspend, your PP account if you go that route. YMMV.