root@johnny [/home/ashrafjp/public_html]# du -h --max-depth=1
284K ./cgi-bin
172M ./ojs
84K ./scgi-bin
2.9M ./luxcal
192M ./limesurvey
1.8M ./advpoll
8.0M ./maillist
16M ./helpdeskz-ticket-faq
324K ./cupertino
668K ./images
51M ./livehelper-chat-faq
24K ./new_items
8.8M ./wikkawiki
454M .
Looks like you've uploaded a few massive folders there for having "no uploaded files or other staff". Anyways, the backup script should be able to exceed the 500mb limit to create the backup, download it with FTP, and then delete it. Do you really need to do whatever complicated FTP thing you're trying to do?