Travel Triangle - Refund for tour cancellation from Travel Triangle

We had booked a tour to Assam & Meghalaya from Travel Triangle from *nd April to *th April. An advance of **k odd was paid towards the booking amount. Now due to country lockdown we asked them for a refund or an extention of the tour for a year with the same price. However Travel Triangle has refused to give refund for this amount and are allowing extention only till **st Dec ****. We belong to service class and our kid has educational commitment, hence cannot plan the trip except for vacations. Flights during Diwali and Christmas vacations are * times the rate at which we booked. I have discussed all my concerns with the representative of travel Triangle, but they refuse to co-operate. Now that i have raised this on social media they have withdrwan the second option of extention till **st Dec **** also and have informed me that not a single penny will be refunded.

How can they charge me this amount for a service which I have not utilized? Request your help in getting a full refund for this trip amount and also wish to claim for a monetary compensation for the trouble faced due to unethical practice followed by Travel Triangle.