Did you ask for the postmaster for that PO? They may not be able to force them, but if you give them a sob story about what you have to go through, they should be able to strongly 'suggest' that they make a little more effort. Either that or put a sign on the box that says "honk" on days you think you'll get something.
Talked to the new Postmaster once last month due to this same situation, she most empahatically told me "This stops now!" , the package in question that time DID show up at my door the next day, however a week later, the same thing. Pink slip in my mailbox, no attempt whatsoever to deliver to my door. When I went to to the PO to get the package, I tried to talk to her but was politely told she wouldn't see me. To be fair to her though, the person I talked to out front didn't even attempt to go get her, She sort of whispered to me conspiratorially "She won't come out to talk to you." Which I found kind of suspicious.
Can you say "Run-around" ?