I know this is quite old, however, would like to answer it.
Could make out in the below lines:
<message from="dest phone@s.whatsapp.net" id="1396425196-49" retry="3" offline="3" type="text" t="1396431017" notify="Luca">
rx <body>Prova</body>
rx </message>
you haven't changed the destination phone number which is why it shows
message from="dest phone@s.whatsapp.net"
and also
Request last seen dest phone: tx iq to="dest phone@s.whatsapp.net"
Just input your destination phone number and your code should be working fine.
P.S. WhatsApi do not support spam, hence, if you do so, your number would be blocked.
Hope this helps.