Order # 614715 cancelled while item still available to shop

Location/place: Delhi

Name of company/service: Deals And You

I have purchased an item from DealsAndYou and they have cancelled my order stating that the item is not available in stock while that particular item is still available on their site to shop but with the increase in price of Rs 100.

First of all, if a particular item is not available with them how can they taken up the order. Secondly, if the item price increased meanwhile they should provide the product to the customer with the older price instead of cancel the order.