Coles will only charge you once for your order

If you notice two payments for the same order on your bank account, one is a 'pending payment' that will be removed within 72 hours.

You may see a ‘pending payment’ amount withheld on your bank account. This is part of the bank pre-authorisation process towards your final total. It’s not a separate payment for the same order. Please be assured Coles will only process the payment once, for the final total, when your order is packed and ready to go.

This means you only pay for exactly what’s in your bags at the point they are packed. Nothing more.