Romeo, I doubt you'd ever get what you paid for that amp, anyway, but hope you have abandoned any thought of passing along the screwing you just got. Get your money back from the woman, if you can. Never assume anything you buy on CL works, whether it's audio gear, a blender, a lawn mower, whatever. If you can't test, don't buy. You might get away with it if you're shopping for anvils. Maybe.
Good luck on recouping your loss. Hopefully, the woman is honest, was unaware that someone had fried her gear, and will refund the money.
Of course, there are two sides (usually more) to every story. What if an amp were fine, but a buyer failed to connect it correctly, or used poor methodology (like connecting speakers with the amp turned on) resulting in damage? In such a case, who would be getting hosed with a return for refund?