Some time ago, I did a writing freelance job for a client. I sent in a few drafts and received very little feedback, despite me prompting for some, but I was given nothing but praise for my work right up to the point that I received payment.
Now, two months after I turned in my final draft and received payment, the client has changed his mind about my work and is very unsatisfied with what he received. He has been sending me unprofessional e-mails lambasting my work and accusing me of things such as trying to make the piece as boring and poorly written as possible (and no that's not an exaggeration, that's what he wrote). I totally disagree with him and I have tried to explain that, having not received proper feedback, there was little I could do about the items he is now unhappy about, but he hasn't seen the light. I feel as though the client is being quite unreasonable and is making this personal.
I'm concerned that this individual might damage my reputation as a freelance writer or badmouth me to other clients. What can I do to try and minimize the damage caused by this situation?
EDIT: To clarify, not many issues were cited as to why he was unhappy with it, but those that he did mention were items that were in as early as my first draft and which I would have happily made changes to had I been asked. At this point though, he's wanting a total rewrite and doesn't want it from me, which again I find incredibly strange because I received praise at every step of the way earlier. I've tried to think of what I could have done differently, but I can't think of anything.
RESOLUTION: One of the answers to this question is what wound up happening. It may or may not have been a good way to resolve it, but it's there for appraisal.