Order from Alpha Dream hasn't arrived

Hi,

I've ordered some scents from Alpha Dream on May 3, 2014 and received order confirmation along with USPS tracking number (I've also inquired about change of shipping method - as I wanted my mones a bit faster, but my request was discovered after the packed was sent).

In accordance with USPS tracking my package left LA on 8 May, 2014 (First-Class Package International Service)

Unfortunately, the package has not arrived up to date (I am located in Eastern Europe, but on May 3, 2014 I've ordered couple of items from US and every one of the them arrived long time ago (usually 3-4 weeks after the date of the order)). I've asked AD for postal receipt/notification of shipment on June 2, 2014, but without success.

Could you please share your knowledge what should I do now? As I understand my shipping method does not provide me with tracking outside US - is there any other way to check what the hell happened? USPS investigation? Postal Inspector? (As I assume they can commence investigation and find out what happend after the package left US, right?)

Best,
A.