Boxer Umzinto falsely advertised

I am disgusted and disappointed with boxer Umzinto manger and the way he handled an issue I had . I saw the Ricoffy advertised with big R79. Price tag was hung in between 2 shelves that was packed with 750grams tins . I was excited with the special price and took a time to pay and was charged R110 . When I askd why I was that the 660gram is on special and not the 750g. It’s not my fault n I wanted it for that price because they falsely advertised. Manager was called and argued the point that it’s say 600g in small writing so I shud have checked and not looked at the eye catching price and also look at what size coffee is packed . He bluntly made me feel silly and ignored the fact that they had the wrong size coffee packed with the wrong price . This makes me very unhappy that staff do wrong work and customers has to be made a stupid . How many other older people must have taken the coffee thinking it’s R79 but was charged R110. It’s wrong . I demand feedback on this and an apology from the manager of the store