Brittany Dawn Davis, a fitness influencer on Instagram, is being accused of not sending people the products they purchased.

Davis offers individualized coaching sessions and ebooks for sale, but multiple followers told INSIDER she sent them months late, and without the promised customization.

In a private Facebook group with thousands of members, followers called her a "scammer" and a "liar."

Davis released an apology video, but many followers aren't convinced.

Brittany Dawn Davis, a fitness influencer with more than 560,000 followers on Instagram, is being criticized by fans who say she didn't provide the services she promised.

Dozens of fans say Davis didn't deliver on e-books, workout programs, and online coaching sessions they purchased, calling her a "scammer" and a "liar," according to comments reviewed by INSIDER in a private Facebook group with more than 2,500 members.

The products can be expensive: On her website, Davis offers training programs that cost up to $300. Multiple followers also said Davis deleted critical comments and blocked them when they inquired about their purchases.

One follower in the Facebook group, Courtney, who spoke on the condition of withholding her last name, purchased a dieting ebook and workout program from Davis in January 2018. She said she received it two months later, after sending Davis multiple messages about it being late. When she ultimately received the workout program, she said it wasn't "individualized" as promised.

"Dating back to 2016 (possibly earlier) she has been scamming clients by not sending their fitness and nutritional e-books, not following through with online coaching, not conducting weekly check-ins, and not individualizing workout packets," Courtney told INSIDER. "Brittany repeatedly deleted and blocked clients who would call this to her attention."

Many of Davis' other followers talked about similar experiences, some of which were reported to the Better Business Bureau in early 2018. The backlash has now built into a crescendo. This week, Davis was the subject of viral critical YouTube video. A Change.org petition signed by more than 6,000 people calls her business "fraudulent" and responsible for "continually scamming and lying to her followers, clients, and fans." People in the Facebook group organized to complain about Davis have asked companies to end their sponsorship deals with her.

Fans weren't convinced by her apology

On Wednesday, Davis published a video in response to the complaints on YouTube, where she has more 300,000 followers. She apologized to people who felt scammed by her, and said that she was overwhelmed by her early success.

"These claims are coming from years ago after I was launched into a business that took off so fast I didn't know how to mentally handle it. I did what I had to do to the best of my abilities," she said. "At times, it was overwhelming and I took on more than I should have. And for that, I take full responsibility and I am sorry."

Several fans who spoke to INSIDER weren't persuaded by Davis's video. They criticized her for monetizing the video on YouTube, and for posting affiliate links in the comments, which would allow her to generate revenue from her apology.

Her timeline of events also contradicts complaints from dozens of customers, who said she neglected to provide products, respond to complaints, and blocked inquiring fans just in the past few weeks.

Davis is also being called out by other people in the coaching business. Kayla Lippens, a certified life coach, has been compiling complaints about her in an Instagram story.

"Can you imagine spending money on somebody who's supposed to coach and guide you through losing weight — and it's an emotional journey — and for them to quit replying and not give a s--- — and then to say it was an accident?" she said in her story. "There are thousands of thousands of women that she's done this to."

Davis did not immediately reply to INSIDER's request for comment.