Sometimes the tracking on eBay's system can be a bit slow to update; however, so long as the tracking details prove attempted or successful delivery of the item back to the seller then you will be able to get your money back, even if you purchased your own returns label as opposed to using an eBay Returns Label to return the item to the seller. There is no need for the seller to update the tracking details manually to confirm receipt of the item as the tracking will update automatically, even if there is a slight delay to begin with.
If the seller does not refund your money voluntarily then escalate the matter to eBay at the first chance that you get, which would be four days after the date that you opened the case. If you do that then eBay will force a total refund of the money that you paid to the seller. However, doing this would result in the seller's account being hit with an account-damaging defect, so it's not really in the seller's interests to mess you around and refuse to issue you with a refund for the item.
