Currently, these companies are granted warrants for up to five years by either the Queen, Prince Philip, or Prince Charles.
Mrs Kenton said there was "nothing" in the book to "be upset about", adding that it was an "unbelievable" decision.
"It is very sad for me that they didn't like [the book] and I'm finding that very hard to accept".
The 82-year-old said losing the warrant "absolutely killed" her and that she regretted "not being wise enough" to omit mention of the royals in her autobiography. She even sent Buckingham Palace a copy when the book was published past year.
Trained at the Berlie Corsetry School, she has more than 60 years in the lingerie industry, and holds a lifetime achievement award from the United Kingdom industry.
For centuries, royal warrants have been issued to trades people and companies who regularly supply goods or services to the monarchy.
Kenton insists that she didn't mean to divulge the royals' private information and that the references to her famous clients were incidental - not salacious.
"Shall I tell you what I do?" she was quoted as saying.
Kenton, who transformed Rigby & Peller into a global retailer after acquiring it for £20,000 ($27,000) in 1982, also explained how Princess Diana had accepted posters of models in lingerie for her sons William and Harry for them to bring to Eton college. "I've had the royal warrant for so long I never imagined that this would happen".
She said she was told by the Palace six months ago that they "didn't like the book" and she shouldn't have the royal warrant any more.
Buckingham Palace said it not "comment on individual companies".
She was behind all the swimwear the late royal was pictured in as she holidayed with Dodi Fayed in the summer of 1997.
The only other notable company to be stripped of its royal warrant was Harrods in 2000.
"The Philip/Harrods case suggests that removal of a Royal warrant is the Royal person's equivalent of expressing publicly his or her serious displeasure - an outlet that they do not have in many other public forums". However, officials from the Buckingham Palace refused to comment on whether this was the cause.
Where does Rigby & Peller have stores and can you buy their products online?
Russell Tanguay, director of warrants at the Royal Warrant Holders Association, confirmed yesterday that the Knightsbridge-based retailer had lost its warrant.
She also claimed to have given Princess Diana fittings.