Mentari book store Kelapa Gading is cheating the customer. Book price written on sticker is Rp. 340,000 but in bill they charge Rp. 381,000. I purchased an additional Mathametics grade 9 book on 6th July.reference number bill JKG901205. I inform this price difference but they refuse to adjust or refund this excess amount Rp. 41,000. In general discount offer in the book from the published price. In this case they are charging 12% higher than published price. Quite surprising to me.