it basically says that I don't have internet connectivity on the Wi-Fi though my phone definitely has Wi-Fi. it doesn't say error but asks me if I wish to use cellular data which I obviously with Wi-Fi don't want to do. I can download but not using Wi-Fi. it becomes far to costly to do so using my data.

Hi Ann, are you getting an error message when you try to download ebooks through the Kobo app on the Samsung Galaxy Nexus? Tell us what happens you try to start a download so we can help you figure out what's happening and possibly how to get around it as well.