Quick question: Did I kill it?

I just bought an Arduino nano and motor controller made specifically for it http://www.robotshop.com/arduino-nano-7-12v-2a-dual-motor-controller-5.html

It was working when I bought it. That could have something to do with the fact that I hooked it up correctly the first time. Apparently this time I connected the leads (the 7-12V ones that provide power to the motor driver) backwards. How did this happen? Because the inscription indicating the direction of current is labeled differently on top motor controller than it is on the bottom. It appears as it should on the website, however.

So basically, now when I connect it to the nano and hook up the 7-12V leads (the right way), nothing happens. No LEDs come on. Nothing. The Nano still works fine, though.

So, I have 2 questions: 1) Did i fry it? 2) Do you think I'd be able to get it replaced at no charge?

Thank you for taking the time to help me out!

If it worke once and now it doesn't... well something bad happened!

If the stencil for voltage on the bottom of the PC board is backward from the top, then I think you should get your money back... although it looked OK on the link you gave.

The board also looks like it MIGHT have a reverse voltage-protection blocking diode, that being the case then problem is likely to be at the arduino end