UPS did this to me twice in about a month's time last year. They told me it was because they had a substitute driver on the route for the whole month and that they were having problems with the new driver. Both the UPS distributing center, and the call center sucked at helping. Luckily everything was insured, but I had to wait another month to get my speakers, and had to find a completely different amp that ended up not working, so a year later, I still haven't gotten a new component amp. Sucks, and I would be surprised if the substitute driver is driving around with some DLS speakers and a US acoustics amp.
/rant