I could understand that but it always seems to happen when I am sending as a large letter through eBay with Royal Mail the tracking number never works and seems that it isn't really included with this postage method so then these items are never updating to being delivered.

Surely your system should be able to update after a certain amount of time or if a buyer can confirm receipt instead of relying on what seems to be none existent tracking information off Royal Mail to update which never happens as it shows in the other two times it's happened from last year that also still show the same.