Action 9 has uncovered new and serious allegations against a high-profile chiropractor who some patients claim charged them for services they never got. There is now a state investigation that accuses Dr. David Darrow of exploiting patients for big bucks.

Eyewitness News caught up to Darrow outside of his clinic.

"We are doing the treatments," said Darrow.

Darrow advertises non-surgical therapy to relieve back pain, but Eyewitness News found at least six patients who claim he collected thousands for high-tech decompression they never received.

"I was kind of scared because that's a lot of money," said Nelinda Bonsignore.

Bonsignore was in pain and desperate, so she paid $14,000 up front. She quit after just four of 20 treatment sessions, so she was expecting an $11,000 refund.

"They gave us the runaround. We called and they never did," said Bonsignore.

In his first interview with Action 9, Dr. Darrow said his past office management had made mistakes he did not know about.

"Some of the complaints, I'm telling you, are valid, okay," said Darrow. He also said he was working on refunding the money.

Action 9 has uncovered new allegations about how Dr. Darrow's practice billed patients. Dave Cimini paid nearly $6,000 in advance for the decompression treatments. He had them all and then discovered the extra charges.

"I had no idea he was billing my insurance company or I would have stopped it a long time ago," said Cimini.

Cimini uncovered pages of charges billed by Dr. Darrow's offices for more than $2,000. Darrow said he never authorized the insurance payments, but Cimini said Darrow signed the paperwork. Darrow's office declined to show Eyewitness News the contract for privacy reasons.

Just last month, Florida Department of Health investigators, in a formal complaint, found evidence he had exploited patients for financial gain. The case involves three unnamed patients. The state accuses Dr. Darrow of charging for services that were not necessary and there was no evidence other services were even performed.

The complaint now heads to the Board of Chiropractic Medicine, where Dr. Darrow says he will prove his innocence.

"I know there are always two sides to a story. I appreciate the chance to tell my story because there are thousands and thousands of patients who are happy with us," said Darrow.

Dave Cimini has filed complaints with the Department of Health and the Division of Consumer Services.

Dr. Darrow says that out of 19,000 treatments, there have just been a handful of complaints. Two years ago the Florida Department of Health disciplined and fined Dr. Darrow because his back pain advertisements created "false or unjustified expectations."