Discovery refuse to honour 15% cashback on Vitality marked Dischem purchase

On the 27th of January I purchased a humidifier from DisChem that had the Vitality sticker on the label. The Vitality mark also showed up on the cash slip. The humidifier cost R354. I have DisChem set as my preferred provider and am expecting 15% cash back. 354 x 15% = R53. The total cashback on the slip before I bought the humidifier was R4.69. On the 22nd Feb when I look at my slip I had only gotten a total of R11.62 back from the purchase of the humidifier. I was expecting that total to be R4.69 plus the R53 from the humidifier for a total of R57.

When I lodged a question with your team, Mogomotsi M said that cash had been credited to me and the 15% would reflect.

When I checked earlier this week, the cash back total I had on my receipt was now up to R40. Which means you credited me with R35 (10% of my cash back) not R53, 15% cashback I should have.

I asked again, now Mmabatho T ignored my question about the humidifier and said that R35 was from medicine bought, indicating that I am not getting any cashback at all for the humidifier. So Mogomotsi did not credit me as promised.

So if I don't get cashback for Vitality marked purchases other than medication, why have the vitality mark on things if you're not going to honour your cashback on purchases?

This has been dragging on for months now and your team still can't seem to get my cashback working properly. If I am promised 15% cash back, that is what I should be getting. I refuse to spend a cent more at Dischem on anything with a vitality mark if you're going to lie about cashbacks.