Bought a used car from small dealer?

I bought a 07 honda civic from a very small dealer in cash. It came with an aftermarket alarm and the fricken dealer only gave me one key. So the key that i have doesn't work. So the alarm goes off when i open the door and the car is basically blocking my driveway. I can't even get in contact with the Manager. I'm only contacting the salesman and he said the 2nd key should be arriving soon. Almost a week has pass and the key haven't arrive yet...