Refund Promised, not received, for delayed 'expo/conference'

Last year I booked for an Expo, which would've happened in January. It was postponed a few days before the date, to March. We arranged our travels, and again, a day or two prior to the promised Expo date, it was 'postponed' to May. I informed them that we cannot change our travel arrangements at such short notice for a second time, as we'd likely not get refunds on accommodation, etc. - note: at that time, NONE of their email addresses worked; I was told on Whatsapp, when someone finally answered, that they'd been offline for that week. I was promised a refund. But, until now, nearly two months after the promise of a refund, I have yet to receive any form of refund for the tickets I'd purchased. Also, none of my queries are being answered at all. Neither on the email address where I had to send my details for the refund, nor on their Whatsapp number where I was initially promised a refund. This is a terrible first experience, I feel ****med, and I will never be using them again.