Difficult situation and I am sorry you are having this problem.
I could offer two resolutions. If you are comfortable doing so, you could undo the 4 screws and see if possibly the button that is under the front cover is bent or out of line with the opening, it should be something fairly simple and it may just be opening it up, lining everything back up and reassembling it may solve it. The button has 2 legs that plug into a small socket and it is red and about a 1/4" around, it has to be something with who it lines up with the opening on the key pad. Short of a major breach of common sense (spilling water in it or overtorquing a screw) you can't really damage anything by opening it and it won't affect the warranty, so if you are comfortable it is worth a try for a quick fix. I am also happy to swap it out for you, just PM me if that is what you prefer to do.