Error in advert itrm number

Makro had full cream milk 18*1l for R109, i bought and paid 159 including delivery. I then missed delivery call and then as I was arranging that i decide to check and track my order, turns out they changed it to 6*1l for 109. I query and send email i also have a screenshot of their advert when i was paying. Below is the response i got: Good day, Thank you for reaching out to us. We do apologize for the inconvenience caused please note that was a Pricing error Please be advised that the sales package for this item states a 6-pack of milk, not 18. We sincerely apologize for any confusion this may have caused. Kindly also note that Makro reserves the right, without prior notice, to discontinue or change pricing or specifications of products and services offered on our website without incurring any liability whatsoever.

Kind regards

The Makro Team,

My question is why am i not given with the price and number They advertised?