Double deductions for Online purchases.

Problem with online shopping at Woolworths. Every time I make an online purchase on my Capitec savings account I end up paying double. A week later after making initial purchase Capitec allows for the same amount to be deducted from my account again. Initially when I contacted the bank they reversed the second payment but now it’s a struggle as I need a letter from Woolworths to confirm that it is not a different transaction. The call Centre agents confirmed that there is a problem from the bank side with online purchases from Woolworths and some other retail outlets. This is immensely frustrating for me. It is a total inconvenience as I have to fight to get my money back. What bank allows double deductions for an online purchase. This is not on Capitec. I am now considering to close my account!!!