Dion Wired not happy with the service

I looked at this special being advertised on Dion Wired Website, On Monday morning I called Dion Wired Woodmead store and asked if they had stock of the LG 24 inch monitor, going for R999.00 they said yes, I then said im driving now to come collect 7 of them , they said they had 30 . When I arrived at the store the lady then tried to sell me 19 inch monitors for R999.00 , she then asked where did I see the adverti*****t, I said on your website , 1stly she then tried to tell me this was only for online deals , which I said it doesnt say that anywhere on the website, then calls there stock controller and they say there isnt stock anywhere and they not getting more, why was this then on the website for the entire weekend and as soon as I was in the store and asked about the deal and there stock controller was checking all of a sudden the advert was removed in the space of 10 minutes , I had seen the advert , then called to confirm it, they lady who answered the phone confirmed it too , but when I get there im told she made a mistake and I had Just Driven 35 Kms there for nothing, this isnt the 1st time this has happened , and I get told by the manager there is nothing they can do yet I wasted my time and petrol . not happy with dion wired woodmead