Refund of air ticket

I booked a flight through Travelcheck Travel Agent in February 2020 and due to covid I was unable to travel until all covid restrictions were lifted. I have been sending emails since the end of 2021 for a refund on my air ticket and the only response I get is mainly automated responses. I have also in the meantime been in contact with the airline and unfortunately they are only able to assist me if I have a RA number for the refund of my ticket. I have since then sent 3 emails to Travelcheck requesting my RA number and I am still receiving automated responses with no RA number. Their service has been utterly poor and there is no customer service support at all.