seagate external hard disk problem...pls help.

I own seagate 500gb expansion portable hard disk for last 6 3 months.
suddenly it showed problems while copying.then when i showed RAW error.then i tried to format it in win7.it showed cant format error.
then i tried it in ubuntu.The DISK UTILITY showed DISK FAILURE IS IMMINENT in SMART.Reallocated sector count showed as failing..
need help..what to do?