If you are a registered user, and you make a data order that's too big to be immediately processed and downloaded, it'll be added to a Data Services Platform batch processing queue. When it's ready you'll receive an email containing a bespoke download link.
You can track the progress of your orders via the 'My Profile' section of the DSP - accessible by clicking on the green head-and-shoulders icon at the top right of the screen, next to your registered user name.
The Orders tab provides a list of all orders you have made to date. For each, the reference number, dataset name and current status are shown. For 30 days from the order date, a download link is also available.
If you click on the magnifying glass link you will see mode details about the order, and you'll also have the option to cancel any unprocessed orders.