I can understand your frustration, but take my word for it UPS (and most other couriers for that matter) often mess up like this. I work for an online retailer, and the amount of times we get unruly customers complaining that the goods turned up late/didn't turn up is truly shocking. It's difficult to explain that the anger shouldn't be directed at the seller, rather at the courier. Of course it is the sellers responsibility to get the goods to the customer, it's often out of the sellers power, especially considering the amount of time you have to wait before the courier deems the parcel 'missing'. 

I'd say give SM a break, try to understand it from their side. It's frustrating, but these things happen.