Graphic Novel Cover

Stardate May 17 2014 The owner of the flash game this is based upon hired me to do this cover. She offered $150 for the work via Odesk. I asked for 50% upfront in my application. After a protracted argument about that Odesk convinced her to pay at least something upfront. She paid $25. I worked on this for a total of 30 hours (including 6 3d mock ups). In total she paid around $1 per hour for this work while she claims she has secured a $5.2million contract with media outlets. Her argument not to pay me is? I did this my own way. What can I say? She hired me based on artwork in my portfolio. Obviously it will look somewhat like my art no matter the reference images..