Warning about Amazon South Africa

Just a warning - I ordered a large order from Amazon South Africa for my small business and was charged twice. It has been 10 days and I am still struggling to get them to refund the erroneous second deduction. That is the end of me doing business with Amazon South Africa. I have over the years had a number of orders with Amazon in the USA and never had this issue. And no-one at Amazon seems to be able to sort this out What is more scary for me is that they were able to make that second deduction in the first place and nobody seems equipped to refund it.