Builders Warehouse on line false advertising

My wife and I are in the market for a Whirlpool top-loading 10kg washing machine. We googled the best prices, low and behold an advert comes up for this machine at Builders Warehouse on-line store. We even visited Builders Zambezin Drive, Pretoria to check out the machine. We were told that there was no stock in store and that we should order it on line to get a better price. That is what we did, we tried on line, but the we site did not tell us that there was no stock, yet we could not get the thing ordered over the internet as it would not allow a selection. They keep on advertising the machine online, but now they say the call centre says they have no stock, is this not false advertising? I am most disgruntled.