Unhappy client

On Monday the 4th May we went to Build it to purchase a boma which was advertised for R439.00 and when i arrived there, a notice was attatched to the boma stating that there was an error in the printing of the Build it pamphlet and is R539.00. I approached management and I was told to speak to the owners wife who refused to take responsibility for the error and reluctantly sold me the boma at the price as advertised I am highly disappointed and feel that they have misled me under false pretenses. I would like an explanation as to how this is acceptable.