delete app from ipad permanently?

I can't seem to delete an app from my ipad permanently.

I can delete it, but then the update app puts it right back in. I was told at the apple store to remvoe it from itunes, but I can't figure out how to do that.

I found a tip on line to just right click on the app and delete it. Right clicking does nothing.

I found another tip saying to select it and hit delete on my keyboard. Tried that too, no joy.

Maybe these tips work on older versions of itunes? Anyway, how do you do this?