Is it legal for a creditor to call and harrass you on your job?

Is it legal for a creditor to call and harrass you on your job? My boss has told them it's illegal. Is this true. They have been told on several occasions to stop.

According to the FDCPA (Fair Debt Collectors Practices Act), collectors must follow these rules: 1) A collector cannot call you after you’ve told them not to do so. 2) A collector cannot call you at work. 3) A collector cannot tell other people about your debt. 4) A collector cannot threaten you (with court, jail or other). And lastly, please don’t ever give a collector your bank account information or give them post-dated checks. You want a written agreement about how the debt will be paid before you pay a cent.

Letter example to send:
(Date)

To Whom it may concern:

I have been contacted by your company about a debt you allege I owe. I am instructing you not to contact me further in connection with this debt. Under the Fair Debt Collection Practices Act, a federal law, you may not contact me further once I have notified you not to do so.

Sincerely,

(Name)

(Account No.)

I say, have fun with it. Harrass them back!
Karma comes back 10 fold, and I personally chose to be the bearer of it.
My own personal debt collector was fool enough to give me his number. Now I call himn everyday, harrassing him until he will one day, beg me to quit.
Teach those who choose the dark path, a lesson in payback.
Never, ever threaten them with personal harm, or anything that could land them in jail, but bring out your best, insidious tone and tell them that black crows are watching them are the bearers of bad Karma, look over their shoulders, bad things might just happen, etc etc.
Just ensure you never threaten them or that could land you in jail for making a terroist threat, so put that disclaimer in there so they don't call the feds on you. They'll be be pissed like all get out for bugging the crap out of them. Oh, and enjoy yourself while you are at it. Guarantee, they will stop calling you.
Ha!