BOSTON -- Some call it a super fruit, claiming that acai berry can make those who eat it healthier and thinner. But the manner in which many acai berry products are marketed is leaving many consumers with a sour taste.

NewsCenter 5's Susan Wornick reported Monday that better business bureaus in Massachusetts and across the country have been flooded with consumer complaints about free trial offers of acai berry products that aren't as they appear.

"These are companies that take advantage of those people that are desperate," said Warren King of the Better Business Bureau.

Viewers who have emailed Team 5 Investigates complain that they ordered a 30-day free trial of acai berry and agreed to pay about $5 shipping, but instead ended up with credit card charges up to $80 or $90.

Another wrote, "What's hidden in the fine print, is that they are going to continually send you bottles of these supplements and charge your credit card $75-$80 a bottle until you call & cancel the subscription."

King said many consumer complain they have a hard time clearing up any misunderstanding with the companies.

"They can't get through, or that their lines or down or that the mailboxes are full or that the e-mails don't work."

After Oprah Winfrey and Dr. Oz spoke about the health benefits of acai berry, some companies began claiming she had endorsed their products.

Winfrey said otherwise, releasing a statement, "Consumers should be aware that Oprah Winfrey is not associated with nor does she endorse any açaí berry product, company or online solicitation of such products, including MonaVie juice products. Attorneys for Harpo are pursuing companies that claim such an affiliation."

Connecticut Attorney General Richard Blumenthal is investigating claims, and the Center for Science in the Public Interest is also warning consumers to avoid free acai berry trial offers.

Further, dietician Leslie Bonci, of the University of Pittsburgh Medical Center, said there is no evidence to back up health claims that some acai berry companies make.

"I don't think we should be excited," she said. "As a matter of fact, I think we should be a little remorseful to pay five bucks for a bottle of something that is not going to make me thinner, or healthier and we can get those antioxidant benefits in other ways."