FedEx stole my kids' Christmas present

I had a relative's pharma delivery recently fucked with - the contents were carefully taken out, and replaced with tissue paper before we could pick them up from the receiving office at our building. We don't know if it was the people in the office, or it was UPS, FedEx, nothing. Worse yet, I see this happening all the time yet FedEx, UPS, etc... have no incentive to help the customer as they are a quasi-monopoly.