Steve, I am sorry to tell you but LEDS right now are a very "hot item" and everyone is trying to make a quick buck on them, and with that comes "VET BAD QUALITY CONTROL!"
As for Diamond themselves I can not speak, but they are just a wholesale/retail company buying and selling and item, you can download there 2015 RV catalog off the internet, with your product and tons of other items (
http://dg-usa.com/wp-content/uploads...d_CAT_2015.pdf)
Many people have changed out there lights to LEDS of late and some brands are good and some are crap, and this is just the way things go today. I did just that a few years back and found a manufacturer that will sell direct, and have been very happy with the price, the service and the products try them out (
LED light bulb, LED light bulbs for home use and cars) you will have to take a few minutes to get your bearings on where things are on the site (not a retail site) but they have been great to deal with and not one bulb has given me or many of my friends any issues in 5 yrs.
So again sorry for you troubles but Happy Camping