I think maybe you don’t understand what I’m saying to you. I totally agree with this and was not disputing it:

does not change the item price at the time of delivery, the customers pays the price shown at the time of order.

This is in their TOS and I don’t think anyone would order from them if they randomly changed prices.

When you amend an order, the time of amendment becomes the time of order, just like at the other supermarkets:

because we had added another item to the order midweek, the original price would have been updated to that days item price.

Makes sense as business practice, otherwise people could schedule for 2 weeks away and wait to add more specials later that do not run concurrently.

I only brought it up because after you had that experience, you thought it only ever revised upwards and I wanted to reassure you it revises downwards as well.

Anyway, it’s all good. Don’t know why I’m defending/explaining Countdown or NW to you. I don’t much like them.