Paid Advisory Opportunity

I was approached by the GLG firm for a paid advisory opportunity. After extensive communication, via email and telephonically I suddenly stopped hearing from the consultant, Rohit Gupta. I had already provided sufficient feedback and information on the subject matter, which was distribution and sales of used heavy duty vehicles in South Africa to the consultant whereafter I was approached for another project. I have since then not heard back from the consultant on the payment that I was promised initially for the first project. I feel that payment needs to be made for services rendered, but contacting them is somewhat of a myth as they do not have usable contact information on their website.