Was there a way to get it from ITunes to my Mac without rebuying it?
No, there is no way to run iPhone applications on a Mac. The processor on your iPhone is different from the Mac and the operating system as well.
Can I get my money back from the ITunes store if I don't want it on my iPhone?
Also no, sorry. Apps cannot be returned. But try to convince the iTunes App Store Support that you made a mistake, perhaps they will oblige.
In iTunes, open the Store menu, then "View Account". Sign in with your AppleID, then open your Purchase History. At the bottom of the list with your Purchases is a "report a Problem" button. Click it and describe, that you bought BeFunky for the wrong device and ask for a refund.