where and who do you contact about a non delivery?

[sandypebbles]

First step would be contacting the seller

If they are not helpful, opening an item not received dispute within the time limit

What was the estimated delivery date?

Where was the item coming from?

Where is the seller registered? 

How did you pay?

[jellybirddesigns]

Have you not read the Buyers Guides?

Is there tracking? If so, what does it say?

Is the item coming from overseas or domestic? (You can tell this by where the seller is registered, not necessarily where the item is located).

Etc, etc....

So many things to consider but at least have a read of the pertinent information about what steps to take in the even that things go wrong.

Provide some extra details so we can at least have a starting point to help you.