Personally, I would do nothing. I know I'm gonna get a few each month and I just chalk it up to the cost of doing business. However, if I weren't me, here what I would do.
I would see this thread:
Revenge Video
Assuming you have the real chargebackers name and hometown, I would make a youtube video about them doing chargebacks on porn sites and use their real name and hometown. I would then post that video in my members area as an example for others. That should reduce the number of future chargebacks you get.
You're welcome. :-)