Only way now is get a refund from the seller saying faulty product. If your seller is using EBAY then your likely to get your money back. Try putting a video on YouTube explaning how it led'd and show evidence that it is fully not working. (I.e Put your battery on the charger showing its fully WORKING and then put it into the laser and turn it on, does not work, so you have evidence). If the laser is from a company, go to your bank and put a dispute on the transaction you bought the blue laser.
If you really want to come in and fix the laser, I will have to see what the laser look like.