No reason to be nice. Simply tell your attorney that you aren't closing until you can have a walk through. Both the seller, the seller's attorney and the seller's agent know what this means - none of them will get paid. In fact, to be even more serious, you can tell your attorney that considering that you believe their lack of response is a sign of potentially suspicious behaviour (something has happened to the home) you will not reschedule the closing until you have done the walk through as you want to be certain that the home is in good shape before even scheduling the closing. That should get you noticed. Good luck, and don't be nice.
Bond New York