The GSP is an eBay Seller Protection program which is run for them by Pitney Bowes.
PBI/GSP collects import fees which they use* to cover appropriate duty and sales taxes for the destination country.
Sellers ship (by USPS or UPS or whatever) to the plant in Erlanger KY, where they are pre-cleared for customs and shipped out to some 100+ countries.
Pitney Bowes does not own any trucks.
All the shipping they do is sub-contracted.
Most of the Canadian shipping is handled by Canada Post, but CanPar and other companies are also used.
We usually hear those other companies named when they do something terrible.
Can you reconstruct the shipping /tracking number on the box?
PBI/GSP have the package in their possession, so they should provide the compensation for damaged goods.
Yes.
And when an eBay Dispute explains that the shipping was through GSP, they do quite willingly.
They have insurance for that.
And they don't want the shipment back, because : what would they do with it? Usually the claim is damaged goods.
Part of the problem here is that no one can understand how the seller managed to ship a replacement through PB.
Part is that you have been dealing directly with the seller and not eBay's Resolution Centre.
*The buyer does not technically pay customs or taxes, those are on record as being paid by PBI/GSP. That's another reason why it is important to state that GSP shipping was involved. CBSA won't refund import fees to the buyer who, again technically, did not pay them.