Horrible customer service with Pick n Pay

Absolutely the worst customer service experience. I made an online order for my elderly grandparents and they over deducted my bank account. When I contacted customer service, they said, “ We apologize for the inconvenience caused to you. Kindly note that the bank sets aside an amount to cover prices that may differ upon invoicing. The final amount is deducted the day before delivery and therefore you are required to contact your bank to release the rest of the funds that they have kept aside.” and “ Kindly note that sometimes Pick n Pay releases the funds to the bank but the bank still places a hold on the funds, therefore, when you contact the bank they can release the money faster.” I cannot for the life of me understand this! Why must I contact my bank to get my money back pick n pay?! I WANT MY REFUND ASAP!!!!