Double charged by Zara Sandton

I have made a purchase online at Zara , on the 1st of December and the money was taken from my account, and the item was delivered on the 3rd and on the 4th I made another purchase online to the same value money was deducted on my account, I then went to Zara tygervalley on the 4th to return the item bought on the 1st and my return was logged and successfully and last night they refunded and deducted the money again from my account and I then contacted my bank Capitec who advised me to contact Zara as they cannot refund me because Zara has banked both amounts already, this is frustrating because it is not the first time this happened and these fees, emails , calls I have to make between Zara and Capitec with no assistance are so annoying I want my money back