Glitch in the system or a money making gimmick? OVER CHARGED

I wanted to do an online order and found that a few things were on special (if you buy 2), so I put two in my cart (which I would not do if they were not on special). When I got to my check out I noticed the total was a little high and ended up double checking and none of the specials were taken into account, and therefore charging me over R100 extra! I don't know if this is a glitch in the system or a money making gimmick but watch out. They are quick to advertise the special but it fails to be captured at check out.

*In addition, when I tried to email their customer help line, both addresses bounced back... Such "wonderful" service.