U.S. Postal Service poor service

I sent a package Priority Mail from Massachusetts to Florida. It took from Monday to the next Saturday to arrive. The only way it got delivered was that a neighbor of the recipient brought it over when it was delivered to the wrong house. When calling the post office they kept saying it was delivered and they could do nothing about. When I wrote about a refund they said it is not a guarented, so there is nothing they can do. Next time maybe a different company would make a better choice