If you've skipped a delivery and want to restore this, you can log into your account and select the `Manage Deliveries' tab.
You can 'unskip' to the right of the desired delivery, as long as this is done before the cut-off for your chosen week.
If you've input a holiday that you now need to cancel then you can go to the 'Delivery Hold' section of your account and select the cancel button next to the holiday dates in question.
Again, you need to make sure you do this before your cut off. The cut-off times can be seen here