Trista.in - Flight Ticket cancelled without any notice and no refund provided

I booked a ticket through Tripsta.in, and I was charged on my credit card. Today, at the airport (check in counter), I was told the ticket (emailed to me by Tripsta.in) is cancelled and refunded to Tripsta.in already. I was not allowed to board the plane - I had to make a much more expensive (***€) booking to make my trip. Tripsta.in are not replying to me and I have lost ***€ for ticket that Tripsta.in gave me and then cancelled without telling me. I even got a print out from the airlines at the checkin counter, to prove that the ticket is cancelled and refunded to Tripsta.in. They just aren't responding to my emails and no one answers their customer care phone number in any country. I want my money back!!!! Tripsta.in order no. F*********