Diode Dynamics is Awesome
 

Ordered some license plate lights from these guys and when they came in one didn't work for some reason. I contacted them about the issue and a new light was sent out the very next day.

Awesome customer service and very well priced.

I can say the same. Great company, products and service.

About your plate liggt....did you try reversing the polarity? Mine didn't work ether until I flipped it around :-)