how to exchange in ear earphones ?

Hi !

I've bought Apple in ear earphones less than a year ago, they still are under warranty and they don't work anymore.

But I can't find how to use the warranty.

Can somebody tell me how to exchange them ?

I've tried all potential number on the box as serial number but the web site always refuses it.

I can't go in an Apple store because it's too far...

Thank you !