Vistara — Ticket cancelled automatically. But no refunds

Hi
I've been struggling to get a response over my cancellation and refund for vistara. I've booked my tickets via third party called mytrip. Due to covid, the airline had cancelled my ticket and there is no refund.
I have pnr rouimx, the airline is asking me to reach out to agent and the agent is asking me to reach out to vistara. I'm trying to get my refunds processed since 20 apr but no luck. This is most disgusting thing to be done as we are already struggling with money in lockdown and the companies are refusing to pay or process refunds