Pick n Pay Online CHEATS!!!

Purchased a whole bunch of sale items on Pick n Pay Online Site on Saturday morning. Got a confirmation of all my requested quantities as being available. Paid via my credit card and received confirmation of payment as well as delivery time.

On Monday morning, i get a call from Pick n Pay dispatch informing me that because of the large quantity that i ordered-my delivery might be a little later than promised- I agree.

About an hour after the confirmation of delivery call-I get another call telling me that my order has been cancelled as there was an incorrect pricing on their online site. I was asked to re-order. While on the line with the lady from Pick n Pay, i try and place my order again. The prices are still the same sale prices from when i placed my order on Saturday-but now it shows that the stock is sold out. ( obviously as many people would have purchased these deals) So please explain me as to why was my order cancelled? What happened to-'THE PRICE YOU SEE IS THE PRICE YOU PAY??' Also note that everything was paid and confirmed-money was also deducted form my credit card-and then suddenly they cancel my order?? Really feel CHEATED!!! I WANT PICK N PAY TO HONOUR MY PURCHASE!!!