Not selling at listed price. Worst staff ever encountered

My wife and I needed a kettle and we took one which was 299. When we got to the till it scanned and indicated it was 369. We then advised them we want to pay the listed price but the staff then decided to give all sorts of excuses even indicating we chose the wrong kettle even though there were no other kettles. They even went to the kettles and took the price tag away so as to remove evidence of this price issue we had. The staff then prodeced to make a scene as we were unfortunately very frustrated with how inadequate the staff were at resolving this issue. Besides the fact that picknpay would not sell the product at its listed price which im sure violates some law, i have never seen such pathetic customer service in my life.