Why pay for Speed delivery if not delivered???

I submitted a parcel at the cresta branch on the 20th of April, to be delivered next day (so registered and speed mail) up until today, it has not been delivered. When phoning on the 28th of April, cresta, I was advised by Calvin ? that he confirmed that the parcel would be delivered the next day.... today your website tracking functionality is not working, so I have no idea where my parcel is? You stole my money, and looks like you are attempting to ***** my parcel as well!!! I am disgusted with this bad service