Can't delete duplicate contacts from the list on iPad

I had to purchase a new iPhone and iPad. Previous I had like 300 or so with one name, and another 3-400 under 'no name' in my contacts list. I deleted them on the computer on the phone, but I cant delete them on the iPad, without doing them one at a time. I can hi light the list of them but then how do I delete them? The duplicates feature doesnt see them. I cleared them from the MAC and the phone and I cant find how to delete them on the iPad. Did this happen from a virus or?? being hacked? If so, how do I protect against these trojans? What is a virus software that can pinpoint this and delete the virus?

Thanks in advance.

[Re-Titled by Moderator]