What can I do legally if I have been scammed by a travel agent?

I am an NRI based out of Germany with permanent residence in Kolkata, and have been scammed by a Bidhannagar-based travel agent who promised me an expedited VFS appointment for family visit Germany Schengen visa for my mother. They took INR 30,000 in advance, gave me false info and misled me. They said visa officers from Germany would approve my request and grant my mother a walk-in date without appointment. The German Consulate said no such service is offered. VFS opens short-term dates on the online portal and I had to book one myself, which I did. The agent refused a refund, falsely claiming that "their contacts" in Germany opened the interview slots on VFS website, and this alone costs INR 30,000. I emailed the concerned PS in detail, with ACP and consumer affairs dept. in CC. Haven't heard back from them yet. As I am not in India, can I register FIR online? Or else, what are my legal options? My mother, a senior citizen and I are both mentally stressed.