You don't need to contact ebay commerce.
Find the email you received when you paid for your item.
What is the latest estimated delivery date shown in the email.
One day after that date, you can open a case saying you have not received your item.
If the seller doesn't respond promptly, unless they have tracking that proves delivery, you should go back to the case and ask Ebay to step in.
Report item not received
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)
