HORRIBLE SERVICE FROM PICK N PAY

I am never ever shopping at pick n pay Kwa-Thema , I'm tired of their bad service and the attitude. I went to shop at pick n pay today, as I'm shopping I happen to buy some nestle hot chocolate refill which is displayed at 39.99 when I get to the till its R56.99, I then tell the lady cashier that I saw it at R39.99 she then calls another cashier to accompany me to go confirm the price. After confirming that I saw it @R39.99 she makes me wait doesnt even tell me to wait for her she's coming she leaves me at the aisle, go talk to her friend and they laugh about the situation amongst themselves. Now I'm following her around as I see the service is horrible and I'm not being told anything I follow her where there's a manager named Johannes she tells him the situation and to my surprise the manager tells me that I was supposed to make sure that the barcodes correspond. I mean, I then ask him is it my job to make sure that everything corresponds in the shop. Johannes then says there is a policy notifying customers pasted on the wall in the store that if barcodes don't match I can't get what I'm purchasing at the price advertised. I then ask to see that board but it was nowhere to be found. I am no longer shopping at pick n pay because this is not the first time this is happening, the last time I complained the manager gave me bad attitude and left me while I was speaking and went and stood at the corner with the colleagues and they laughed and gossiped. It's too much, I've been shopping at pick n pay my entire life and this is a lot honestly it's enough. After keeping me in the store for 30 mins they still didn't give me the product at the price I saw it.