I called the main number to ask if they could sort it out and the very polite CSR took my information and created a case. It's important to note I had a textbook and cat treat ball from Amazon "disappear" after being supposedly delivered several months ago with DC that Amazon had to replace. Strangely enough my neighbors and I have gotten all our packages from UPS and FedEx without any issues of theft or non-delivery. In fact one was on vacation and a medium sized box sat outside her door for almost three weeks before she returned home without being touched (we don't have the kind of relationship to take in each others' packages).
After creating a case and never receiving a return call last time I decided to just go to the local PO and ask if it was there. The CSR was very nice and helpful, didn't locate the package, but knew my regular carrier was working that day and said he would talk to him. I left my name, address and number with the confirmation number. Another woman was there as well trying to find a lost package.
I'm not holding my breath about getting my package. My mom feels awful that she didn't pay for a required signature since she invested a lot of time shopping and is worried about paying to stop the check before someone tries to cash it. There is no reason the carrier shouldn't have knocked on my door and delivered it so I haven't a clue where it actually went and I'm not sure that requiring a signature would have made a difference if she decided someone in another building would appreciate it more than me.