Well if it is a mistake then they are well protected in the T&Cs:
6. We reserve the right to amend technical or clerical errors in any order without notice. In addition, you shall ensure that all details contained within the order are correct and we shall not accept any liability for any error or inaccuracy in any order.
7. After placing an order, you will receive an email from us acknowledging that we have received your order for the Goods, and the delivery services you have requested from the delivery service provider. Please note that this does not mean that your order has been accepted. Your order constitutes an offer to Evans Cycles to buy Goods. All orders are subject to acceptance by us, and we will confirm such acceptance to you by sending you an email that confirms that the Goods have been dispatched by the delivery service provider (the “Dispatch Confirmation”). The contract between you and Evans Cycles will only be formed when we send you the Dispatch Confirmation.
8. The contract will relate only to those Goods whose dispatch (by the delivery service provider) we have confirmed in the Dispatch Confirmation. We will not be obliged to supply any other Goods which may have been part of your order until the dispatch of such Goods has been confirmed in a separate Dispatch Confirmation.