Takalot.com False advertising

I bought bar chairs and paid for them that were advertised under sale items for R5, I paid R30 extra for an option of picking them up the following day from Fourways Pineslopes, after 10 minutes they sent an email saying the chairs are out of stock but when I go on their website and check the chairs are still there but they change the price immediately after I paid for them even today those chairs are still there.