Kylie Jenner has a lot of nerve threatening a company that will freeze off your fat ... just because the model happens to vaguely resemble her ... so claims the company.
Dr. FatOff is indignant after reading our story over the weekend ... that Kylie is contemplating legal action against the company for deceiving prospective patients into believing she's endorsing him.
Dr. FatOff's lawyer fired off a scathing letter to Kylie's legal eagle, informing him the model is none other than the daughter of one of the company's managers ... and is nothing like Jenner.
The letter says the model, Cassandra, is primarily Latina and Indian. It goes on to say Cassandra, an aspiring model and singer, was hired for her own look and not because of some vague resemblance.
The letter tells Kylie and company to pound sand. Ed Meyer, the rep for Dr. FatOff, tells us the billboard is staying up.