Mytrip.com complaint: being ignored, issued with a void product

My flight was booked for 4th April 2020 from London Heathrow to Bali through the travel agency ‘mytrip’ (Corp. ID no. 556538-1265) with Malaysian Airlines. The cost of the total return flight was £1,002.19. Both flights had a stop over in Kuala Lumpur. The airline cancelled both these flights but the London flights (both inbound and outbound) still went ahead. Due to the UK being in lockdown at the time with a ban for all international travel, I was not allowed to take these flights. I was unable to contact ‘mytrip’ at the time even though I tried for over a month. None of the email addresses nor phone numbers provided by the company were working. On the 7th October I received a travel voucher to be redeemed by the end of June 2021. The agency did not provide an option for a refund. I checked the voucher which is not working as it doesn’t allow me to fly whenever I want. I am therefore not able to use a service I paid for. I managed to call the company on the 27th May who agreed that I cannot use the voucher but have not provided any compensation nor support. They said they would call me back which they haven’t. I have not received an email either. They know that they cannot provide the service they claim and are basically keeping my money. If a customer cannot fly due to a national lockdown, they’re legally allowed a refund.