Items being advertised as "on sale" but they're not.

Product: 32"-55" Full Motion Cantilever TV Wall Mount Bracket

I've been tracking the price of this item for days to take advantage of Black Friday sales. From 17 to 19 November this item was priced at R278.

On 20 November I see that it's on sale at 34% off, only to notice that the they've listed the original price at R599 and the "sale" price at R390!!!

So I'd actually be paying MORE for an item that's supposed to be ON SALE!

I noticed this with several SA merchants. How can this be allowed?