Consumer Redressal

This is to bring to your notice that on 15th August 2014, I placed an order (Order ID - 2626886062) having four different items. When I visited their site on 18th August, I came to know that out of the four items, three items were automatically cancelled whereas the fourth one is under process. I was stunned with this unwanted and undesired actions from thier end and simultaneously failed to understand the reason and logic behind the cancellation and that to without intimating me, which is a serious concern. Neither they are able to give me a clear response nor justification for cancellation. Please suggest how to proceed further.