How can I track an eBay parcel which lists tracking number but for postage carrier says other?

I have attempted what you are trying to do. Wait until the last due date and then ask ebay for a full refund.
Many have used the phoney mail package routine. Be certain to take the name of the company. (They have been known to switch names quite often.)
With less than 500 orders I have not got any true experience, yet look and see the rating for anyone you order from. I also always now look for standard delivery. Economy delivery is almost non existent.
Pay the shipping and be certain the cost is viable.