Poor customer service

I booked a car hire in January 2020 for 13 - 17 July 2020 and Just Care Hire debited my credit card. Due to the corona virus I had to cancel which I did on 18 March 2020 and requested a refund. I have tried to phone them but the recorded message tells you the office is closed due to the lockdown please send an email. I have sent numerous emails but have had no response. Very disappointing as I have used them a number of times but poor customer service.