Reliance Mart — Price Variation

I shopped in the Reliance Mart, Cantonment, Trichy yesterday. I found a stainless steel vessel set for Rs. 180 in the display and I went to bill all the available stock of 65 sets to the cashier and there the price came as Rs. 189. The incharge of the store tells that the lesser price was only on the previous day and today it Rs. 189 only. It is the staff's or incharge's fault of not changing in the display. You should provide customer satisfaction by giving it in the price of Rs. 180. This is almost overruling the customers and not being fair. Displaying one price and invoicing another price is not fair at all.