Fast Food, Slow Brain: how to alienate your customers with a simple lawyers letter

On the weekend I got an interesting email. The guy who wrote it was clearly terrified, which makes my blood boil. I have no way of knowing whether anything written is true, because all the specifics that would allow for verification are missing, as you will see:

I came across your story whilst searching for info about a consumers rights to blog their opinions and the implications of defamatory High Court Action.
I will not mention the companies name suffice to say the person who wants to take legal action against me for defamation is a franchisee of a large fast food corporate in South Africa.
I waxed lyrical on hellopeter.com and also sent copies of this to the franchise head offices and to the mall contacts from which the franchise operates.

Some facts

The corporate is one of the largest in South Africa in that industry.
I have been in touch (telephonically and electronically) with the Corporate executives - they have apologized for the service I got from the franchise branch and I have kept all emails as a record.
I considered this matter closed until the franchise branch owner (franchisee) sent me a letter via his lawyers demanding I retract my statements which they claim have damaged reputation & business.
They threaten that all costs will be for my account.
They threaten High Court Application against me by next Friday.

My take:

I know I am in the right in this issue.
My problem is that I have no idea of what the costs are for a High Court action let alone hiring a lawyer to defend me.
I was even thinking that if this got so far that I would defend myself but my lawyer skills go as far as Boston Legal or LA Law tv show episode. I'm sure I could pull of a few jokes in court but I dont think that would win me anything.
I am not by any means rich. I was thinking of using my bonus (which i get next month) and if things really get bad selling my car.
The "F$%* You" attitude in me tells me not to back down whilst the scared part (I admit its there) tells me to send a two liner to the lawyers retracting my statements.
The similarity in our situations is BIG CORPORATE vs little man.
Some advice from your experience would help

I'm not sure how much of my experience will help in this specific case, but it ocurred to me that the franchisee is behaving like an idiot. First of all, any restaurant owner who sues his customers for complaining deserves to lose his franchise and all his money. Restaurant reputations are won or lost on good service, and any business owner who doesn't listen to his customer complaints is a loser.
I sincerely hope that the Head Office guys get hold of the franchisee and fire him or take away his franchise for potentially screwing up their brand reputation.
If the lawyer who sent the letter ever reads this, I think he is being unprofessional and extremely stupid. He should have advised his client against such an action, and if pressed he should have refused, if only to save his reputation. The consumer site HelloPeter.com has systems and methods in place for dealing with abuse of unreasonable complaints, and if this complaint fell outside that category, and assuming it was truthful, I suggest that the lawyer goes back to law school and apologises to his lecturers.
Launching a High Court action is tactically suicidal, because of the associated publicity and public interest. You have to sue for more that R100,000 for the High Court to be interested, and you have to prove actual losses in order to claim damages. How do you prove losses from lack of sales based on a complaint on HelloPeter? You can't. Case dismissed. Lawyer looks like a bumbling idiot, client ends up paying costs on both sides. Client loses a good reputation, and gains a new one: Mampara of the Month.
There is a Facebook Support Group for bloggers who get sued in cases like this.