Directory=>"\\B2R6A056A\wwwroot\Amexpmo\login\amex\raman"

I guess this is a Windows machine, and a network drive? (The latter seems like an extremely silly idea to me. IMO sessions should be stored on a local drive.)

Please double your backslashes. That is necessary so perl will use them as a single backslash.

Directory=>"\\\\B2R6A056A\\wwwroot\\Amexpmo\\login\\amex\\raman"
[download]

or, following erix' advise in the Chatterbox, replace them with forward slashes:

Directory=>"//B2R6A056A/wwwroot/Amexpmo/login/amex/raman"
[download]

Do take care to make sure the directory you indicated actually exists, I don't know what exactly will happen if it doesn't exist, but I'm pretty sure perl will not create the directory for you.