Incorrect price of goods on the shelf

I went to Makro Springfield on Sunday morning (19/04/2015) as soon as the store had opened. I was looking for a Home filer box from the Stationary section. I found the \Tidy Files Home Filer"marked for R99 on the shelf. The sales person assisted me by getting it off the shelf for me and advised it was a good buy. I go to the till but the price that was rung up was R349. I was shocked and told the Cashier that I saw it marked for R99. I then had to wait for 30 minutes before a salesperson came to the till. While waiting"