An iPad isn't really a computer replacement, but a compliment. Kind of like coffee & donuts. They are good together and also good independently. If you are feeling buyer's remorse I understand since the iPad is not inexpensive. But I suspect if you keep it you will find unique ways to use your iPad that you would not use the MB. I think it's safe to say most of us here have at least one Mac in addition to the iPad.
If you are going to return it though, BB would be the easiest & safest way. You could EB it but to get to top $ but you have likely would have to send overseas which is always a gamble.