Amounts deducted from my bank account is more than the actual invoice - Online shopping

I've been trying to understand why my online order amount totals differ to what Pick n Pay has deducted from my bank account and called the call center to find out. The consultant explained that one of my items had to have changed that's why the amount differs (the amount deducted from my account is more than what was showing on the invoice. He then stated that I have to call my bank to ask them to reverse the charges and put the correct amount through. This is not practical and incredibly inconvenient. Something told me to check my previous 2 orders and I found that both those orders are also less than the amount deducted from my bank account. Shopping online is meant to be convenient. I simply do not have the time to call my bank every time the incorrect amount gets put through. Pick n Pay please advise? Order number Date of order Invoice Amount Amount deducted #*** 11 Sept 2020 R570.88 R580.66 #*** 29 July 2020 R1,710.20 R1,757.24 #*** 3 July 2020 R462.96 R475.05