Honour Prices!!

I was doing online shopping on Sunday evening between around 8h30, had items in my cart and went to check out. On check out I could not complete payment because fields to select date and time for delivery were not available. I then tried to select to do a collection from a store but again date and time for collection were not available. I proceeded to carry on shopping thinking it must be some glitch i will try to check out after again. As I was shopping I noticed that my shopping total had gone up so I checked my cart and the one item I had in my cart which was loaded into my cart at a price of R75 had gone up to over R100 a pack. I sent an email complaint and got no response. I phoned today to follow up with complaint spoke to Lungelo and was advised I should have phoned in on the night in question and that phone calls from my mobile are free to the customer care number? really? What he forgot to take note of was that the call centre was long closed past 9pm on a sunday. He gave me a reference number for the call and called me back after a while to inform me that he had escalated matter to the Regional centre and they had returned on the escalated incident to inform him to inform me that as it was a special which was being run and the special is now over they cannot honour the price I saw when I went onto their online store to make purchase and the price items were loaded into my online trolley as the special has now passed. My issue is that my CONSUMER RIGHT is the price I see is the price I pay. another issues is How do Pic N Pay Rainchecks work if they give it to you during a sale, and you can come back after a sale and they still honour price? When I asked Lungelo this he could not answer. All I want is to pay the price I saw and loaded my cart with which I would have had delivered by now had your systems not being an issue on night in question.