Why not write an email to the production companies who brought this concert to Doha as well as the beneficiary "Bantay Bata 163". Bombard them with emails and links to the topics here.
Tell them your story and ask them not to deal anymore with this person. So next time Gary V comes along you won't be tricked again.

Here are the contact:
1. Gary V live at 25 website:
http://www.garyv.com/

2. Manila Genesis:
http://www.manilagenesis.com/home/contact

3. Bantay Bata 163:
http://www.bantaybata163.com/contact.asp

Hope it helps.