Unhappy camper

I bought a pair of sneakers from [URL Removed] and paid an extra 100 bucks to have them delivered in a specific date. I was sent a confirmation sms to remind me to expect my parcel the day before it was meant to arrive. Today is the day of arrival and I haven't yet recieved my parcel. Not so much as a courtesy email to inform me that my parcel will be delivered late (or not at all?). It is now 19:34 and I am yet to receive a parcel that was meant to get to me before 2pm. What exactly did I pay the extra 100 bucks for, then? Moreover, what if I needed the parcel on this specific date for a particular reason (eg a birthday) and it didn't arrive? This is shoddy service and I am extremely upset that this has happened