Not all sellers use tracking numbers or mark items as shipped.
One week is not considered long for delivery even between destinations in Canada.
You ave a maximum of 45 days in which to open a dispute although I would never wait that long.
If your seller is in Canada wait one more week.
If your seller is in the USA or International wait two more weeks.
Then click here to open an "Item Not Received Dispute" after opening the dispute escalate it to a claim as soon as the system will allow.
http://pages.ebay.ca/help/buy/item-not-received.html