NON REFUND OF OVERPAYMENT ON INTERNET PURCHASE

On 7th December 2020 I purchased an item on line from Edgars. For some unknown reason the order was duplicated and I was charged for the item twice. As the order was placed after business hours, I phoned their Customer Care Line first thing on 8th December and got a reference number and was advised that the refund would be made in 3 to 5 working days. The goods ordered were duly delivered including the duplicate item. On 11th December I received a phone call from an unidentified source asking for me to send a picture of the duplicate item to webqueries@retailability.,co.za which I duly did having established this was one of the Edgars addresses. The duplicated item was collected by Dawn Wing on16th December. Not having received the promised refund in my Bank Account, the original payment having been made by Debit Card, I wrote to *** on 29th December. I wrote again on 4th, 5th and 8th January 2012. Not having received a single response, I have phoned every number I can find listed for Edgars totaling 37 times. I have been abused, give false numbers to call and had the phone put down on me. I have tried to phone their Head Office on the number listed on their website but it goes unanswered. Finally on 8th Friday I wrote on the Head Office site email giving my details and asked to be contacted. Needless to say it has gone unanswered. As the amount involved is in excess of R1000 I am not prepared to write it of to a "Bad Experience". Is there anyone out there who can help me?