EBay has been around since the dawn of internet time, and some of the programs are kludgy.
Did you pay with Paypal? If so, check your account and if it shows as Paid, there will be no problem.
Many sellers don't use tracking, especially on low cost items, but you are covered by eBay's strong Buyer Protection Program.
If you have any further problems, don't be afraid to ask your fellow members here.