Bargain price changed

My lecturer passed by Dion Wired on the 11th Feb 2015, and saw a Nikon 700 flash on the demo table priced for R1950.00 incl vat. He then asked an employee (Lester) to keep it as one of his students might be interested. He arranged for it to be kept for me for a couple of days. I went there on 13th Feb 2015 to see if they have kept it, they did, but when we got to the price it suddenly changed to almost R3000.00. My husband then said how can they just change the price? Floor staff could not assist so they called the manager. He just then explained that head office changed it and that is how it is. I am utterly frustrated with outcome of this scenario as I have previously spent almost R12000.00 on camera and other goods at this store because of good service and great specials. I don't see myself conducting future business with Dion Wired if this is the way they do business.