Bad customer service

Click is currently running its 3 for 2 promotion on John Frieda products. I visited the Clicks in Kathu village mall. I wanted to buy the 3 John Frieda products that was not in the same rage of hair care products, at the till they told me that the product had to be in the same product range and that I can't mix and match, while the promotion clearly say ANY 3 John Frieda hair products. They refused to help me and kept saying its not "mix and match".

I went to clicks.co.za were the same promotion is running, added exactly the 3 products that I wanted and I got the one free like I should've..