USPS Fraudulent practices RENO, Nevada

I recently shipped a package through our main USPS facility; using priority mail, insured, and signature confirmation totaling $27.20 in fees.  This was done on 3/1/2012 with the package to arrive at the destination on 3/5/2012.  However, the clerk obviously did not label the package accordingly as it did not arrive at the destination until 3/10/2012.  
I immediately went to the facility to inquire about a refund and was told that the only service they "guarantee" is the Express Mail service.  So, basically they are committing fraud by collecting monies from the consumer to enable them not to have to render the services that you believe you are paying for - this is deceptive, and intentional in nature - all against the law in most entities; however, the USPS seems to be in a legal league all by itself.  

 The BBB and attorney generals office cannot get involved in these complaints as I have contacted both entities.  Now this may not seem like a lot of money to anyone but it is the principle involved.  As an educated consumer, I believe in knowledge being power.  And I don't appreciate paying for services I didn't get.  If I get lousy or great customer service; I let companies know either way.  But, when it comes to screwing someone over; and intent is there but I have no recourse, I get pissed.  
Because I paid cash for the transaction my recourse is more limited.  Had I used a credit card I would have already filed a dispute with the credit card company.  So I will just get the word out and maybe inform more consumers so they won't get screwed over like I did.  

 The USPS doesn't care, they stated as much.  But I know that the item basically got shipped parcel post and that is not what I paid for - what I paid for was much more costly.  Be an informed consumer and if you have to; use UPS, FEDEX, etc...  There's a reason the USPS is going broke, but with the money it makes off of these types of transactions, they should be in the black imo.