Hi Shabnam, retailers do change their prices from time to time and do not give us advance notice when this is going to happen. Ultimately, you will have been presented with the correct price on the Dunelm site at the time of ordering so were not deceived in any way. You are, however, entitled to cancel your order and request a refund.
https://www.dunelm.com/info/help/returns-and-refunds
I apologise for the inconvenience and thank you for taking the time to get in touch.