You can try pairing the keyboard with another Mac or iOS device, but if the issue follows the keyboard, you will need to get the keyboard itself replaced.
There is no way to re-bind the Enter key to another key unfortunately.
Did you buy the keyboard with an Apple product, or separately? If it was purchased with a product covered by AppleCare it can be replaced free of charge unless they can show you damaged it, and even if you purchased it separately, it has a 1-year limited warranty on it.