False Advertising

Evening ...I have to say i am disappointed in how you guys handle your online inventory... I just ordered a couple of items this afternoon (Order: ***). I initially ordered items in the amount of R400, that was not enough as i needed to checkout the cart with a minimum R500. I then had to add 2 additional items, now to my Suprise i just received notification that the critical items in my cart are not available, with no option of cancelling the order... But what baffles me is, I went to your site again this evening and when I tried to check out the same unavailable items, it is now in stock... is this your way of luring customer to order items you know is not available so you can capitalize on delivery charges?