want to recover 1 deleted message

I deleted a message from whatssup. how can i restore in the same conversation? I sent the message to a person. However, only 1 grey mark was coming. Also, I saw that the "last seen" has not changed at all and profile pic and status are also not changing since Jan 04, 2015. I thought that the person has blocked me and that's why i deleted the message which i sent to the person. Please tell has the person blocked me? and how can i recover my sent message which I deleted.