If you are fairly handy, and you can't replace the pin, you may be able to straighten the threads a bit using the end of a utility knife blade, very carefully reshaping the threads (you will need magnification glasses and a bit of talent). My husband did this on one of my 510 pins in a tank, and was pretty successful. He has steady hands and a lot of experience. If you have a threading kit, that may be of use as well (although my husband said he couldn't use his, because my 510 pin wasn't standard to his kit. The exacto knife and a lot of patience can work, if the threads aren't too destroyed.
Be very careful when screwing/unscrewing tanks, you really want to not overtighten or mis-tighten. Tanks don't need to be screwed down with a lot of pressure, that usually means something is going wrong. Mine wasn't a mis-thread, but a drop, which misaligned some threads.
Best of luck, if it's new you may be able to warranty it.
Anna