Some years ago when everyone was developing websites, some enterprising people starting scarfing up all the .com names that big corporations would use, e. g., Ford.com. Bayer.com, Kleenex.com and it didn't take long for the corporate lawyers to bring to bear the trademark infringement theory. Others just paid a ransom. I am surprised these shenanigans still go on, but for the scent of money. I think you did the right thing and I think you might have to push a little harder. As an alternative, you might try registering as a .org or .biz, unless they cabbaged those, too.