I had a broken Lasermax guide rod sight for my G19 (I think that's why I got such a good deal on it when I bought it, he didn't know it had a laser), and tried to replace the batteries. No go. It sat around for a year or so and I sent an email recently to Lasermax to see if they'd look at it.
They said yes, send, it, and I did last Friday, not expecting to hear much. It arrived UPS today with the correct batteries in it (user error) and it works great. Value added to my G19, and a quick response from a company who I'd never bought anything from, standing behind their product. So, I'm saying thanks and spreading the word.