What are you rights?
You are entitled to get your money back if the airline cancelled your flight. You don't need to accept a voucher in this case.
The airline must refund the money within 7 days source but what do you do when the airline does not respond to your mails and letters and their call center isn't doing much either?
It happened to me when Easyjet cancelled a flight in July 2020. I was supposed to fly from France to Berlin in September 2020 but Easyjet cancelled the flight. They offered me a voucher to buy another flight or a refund.
I filled out the refund form on their website and waited for Easyjet to wire me 189.- Euro. I reminded them by mail again in October 2020.
Your options if the airline does not pay
I decided to go with a debt collector when I didn't hear back from Easyjet three months after they cancelled my flight.
The first options I googled were agencies which help enforce flight rights:
These services are probably the fastest option to get a refund. The issue I have with these services is that you have to pay them while I wanted the airline to pay for the debt collection. I wanted all my money back and let Easyjet pay for the charges.
How to use a lawyer to get your money back
I picked a lawyer in my neighborhood and paid another 81.- Euro to him to handle the case.
Easyjet did not react to any of his letters so we brought this to court.
The Amtsgericht Wedding charged me another 105.- Euro to handle the case. There was no hearing and in March 2021 a judgement was passed which Easyjet accepted. I received the first chunk of the money in April 2021, 9 months after my flight was cancelled by the airline.