I initially was going to tell you that you did not need a invoice in order to pay for the item but then I saw that the item is listed as; ships to: United States. Did you get the seller's permission to bid on the item? The seller may be ignoring you since they do not ship to Canada.
I didn't see a relist for the item as you stated. I saw similar items but from sellers who have been ebay for quite some time. Perhaps you were mistaken about the seller relisting the item using a different name. If this is not the case, provide the item number of the relisted camera.
**********************************************************************************
Non payers should get unpaid item strikes and be added to block bidders lists. Period.