Can´t reed my Card Extreme III SDHC of 16 GB

Some one can help me to recover my SDHC Extreme III Card, Class 6,  I bought  two cards but one of this don´t let me do nothing , can´t format,  can´t read, even my card reader for SDHC showme no card  is in !!!

its a bad card. it will need to be replaced. contact sandisk support 866-sandisk.