Many people have challenges downloading to the iPad and mobile phones.The iPad is not able to download files easily because it was not developed to be a storage device. To be able to download any type of file, you will need to first install a special App.
iPad app review

You can always download the file on to your computer first and then transfer the file over.

We also have a feature that allows you to download to your DROPBOX if you have that type of account. Then, you can listen on your mobile direct from your Dropbox mobile App.