takeALot can't deliver as promised

I ordered a few items, including a not-so-cheap mouse on the December 31, all of which were in stock and available to be delivered immediately, and for an extra R90, I was promised "same-day delivery". I paid everything including the same-day delivery fee. Later in the day I received my order, except the mouse, which was the point of the order. The app order tracker was updated to say the mouse would be delivered on Friday the 3rd, much to my annoyance! Now on Friday the 3rd, the app order tracker is once again updated, now saying delivery on Tuesday the 7th! How come, if I was promised same-day delivery, and paid an extra fee for the same, can't they fulfill their promise? If they can't deliver as promised, then they shouldn't promote the idea that they can, especially for such an expensive item! Very annoyed! Goodbye takeALot, hello Amazon!