USPS has been awful getting my stuff to me too. My entire apartment building went almost 2 weeks without letters because the delivery man lost the key (I know this because he flagged me down after that time as I was entering rhe building to hold the door for him). Missing bills, packages, paychecks, etc. My last paycheck was torn down the side too. And between my building and the sister apartment building we get packages delivered to the wrong place constantly. I find myself usually once a week or so bringing packages from our building to the other one or they'll just sit there.

Only real solution is to go to your building and ask directly for your stuff. I even offered to buy the postman a replacement key but they didn't take it