Refuse to refund me my money

I made lay bye online to Russells store JDG, The total lay bye was R6349 and I paid a total of R6720. I have sent an email '***' and countless emails to *** and there has been no response since April 2020. The bed was delivered, bu have been asking for a refund for the overpaid amount no one is willing to help. I have had terrible experience with the worse customer service from the staff. No one seems to be willing to help with the refund