Kurt Denke's response to Monster was legendary, and can be found here.
Notice that he doesn't admit, concede, claim or offer anything at all. Just asks for a proper claim to be stated, and makes a few salient observations.
In your position, I'd get a lawyer like Kurt Denke to write my response to the BSA.
Coding is easy; All you do is sit staring at a terminal until the drops of blood form on your forehead.