Jet Airways — flight problem

Hello
I'm writing this complain with regards to the problems i've faced because i booked your flight
I booked my holidays along with 2 other passenger on the 4 of november 2018. My departure date was 8th april 2019 from london to goa and arrival date was 14 april 2019 to london
Around 2 days ago i received an email stating that my flight was cancelled. When i called customer care they told me i get a refund for around 500 pounds for 3 people and they said they will process it
Now when i go to check the price for a one way ticket to london for the 3 o[censored]s it comes twice as more (About 2 lac rupees) than what i paid for a return ticket
I dont find it's fair in anyways that we have to pay that amount even though we aren't at fault
I hope you acknowledge our problem and resolve it
Thank you