Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Screwed by Post Office

The product was delivered, unfortunately, the Post Office is responsible for the missing CD's. Upon delivery, the Post Office failed to secure the mail box, and the empty packaging was found outside the mail box, which was locked in the "open" position. The PO states that it's the seller at fault because it was'nt insured. The PO has failed to act on my claim. Though the theft is not the sellers fault, I found it impossible to reach the seller.