You may notice two payments in your first week: one that was taken when you set up your first repeat deliveries (this will be immediate), and one three days ahead of your next delivery week. This second payment is for next week's delivery, and will fall on the same recurring day each week.
If you've been charged twice and it's not your first week on the milkround, please get in touch via 'Account' and then select 'Help' to reach the team.