Winscp.com Log file creating issue

Hi There,
I am executing the below winscp command:

winscp.com /console /log="C:\Winscp_testing\WinSCPlog.txt" /script="C:\Winscp_testing\sample.txt"

and my content of the Script (Sample.txt) looks like below:

option batch abort
option confirm off
open sftp://username:password@xxx.com
cd dev
get *.pdf c:\test\
close
exit

I am geting a File Not found error when I execute the commands seperately.
when I execute the Script it is not creating the log file as I specified.

Could someone let me know the reason why the Log file is not created?

Regards,
S.Sasidharan