COLUMBUS, Ohio (WCMH) — Millions of Americans turn to grocery delivery apps to save time and avoid crowded stores, but thieves are taking advantage of apps like Instacart, leaving local customers with little more to show than an empty fridge and a high credit card bill.

Lawrene Harchaoui works a full-time job, owns a design studio, and has three children with her husband, who also works full-time on a different shift. To make life less hectic, Harchaoui started using Instacart for grocery delivery toward the start of the Covid-19 pandemic.

“We’ve always enjoyed Instacart. We’ve used it for Aldi, we’ve used it for Kroger,” Harchaoui said. “I’ve always gotten my food. They’ve gone above and beyond to make sure the quality was good — of the food. So I really haven’t had any issues at all, I would tip them extra if they did a great job.”

Harchaoui was waiting on an order from Meijer Sunday when she noticed some strange activity.

“It looked like (the shopper) was shopping really quick,” Harchaoui said. “The quantities that I had in the system– let’s say I bought just one piece of food, like one bag of cheese or something, she tacked on 15 bags of cheese.”

Screenshots of Harchaoui’s order show the shopper purchasing at least five times the quantity of each item Harchaoui ordered. What was supposed to be a $125 grocery bill came out to $300.

“I was waiting on (the shopper) to get here to ask what happened. She never showed up,” Harchaoui said.

Harchaoui reached out to Instacart’s customer service, which sent another shopper to fill the order at no extra charge. The second shopper also racked up a high tab and didn’t show up.

“I don’t want 10 bags of lettuce,” Harchaoui pleaded with the shopper through Instacart’s messaging function. “Please stop!!”

A screenshot of the messages shows no response from the shopper to eight messages from Harchaoui.

Instacart issued a refund, which takes five to 10 days to process.

“I was pretty upset. We have a very set budget on food,” Harchaoui said. “We had other bills that were coming out that week.”

When Harchaoui posted her story in a local Facebook group, multiple people commented and claimed they had similar experiences.

The Better Business Bureau of Central Ohio also received similar complaints against Instacart.

“The amount of my order was originally $187.00 approximately. The contracted shopper by the name of ‘Corina’ charged an additional $150.00 for diced green peppers!!! My order that was charged to my card was a total of $361.35. Corina, Instacart shopper’ did NOT deliver my order but order was marked as delivered online,” reads one complaint.

“I never received the order and was charged over $200 because the shopper that was shopping my order bought two $75 gift cards and charged them to my debit card,” reads another.

The BBB gives Instacart, which is based in San Francisco, an A+ grade because the company promptly addresses consumer complaints.

“It’s not hard for Instacart to figure out who the bad actors are, and those people can be terminated. They could even face criminal charges,” said Lee Anne Lannigan, investigations manager for BBB of Central Ohio.

Lannigan said Instacart uses Checkr, Inc., a third-party company, to conduct background checks on shoppers. She advises customers to select the “no substitutions” option in Instacart to add an extra safeguard against shoppers going rogue, and to contact Instacart’s 24/7 customer service center if something goes wrong.

A Columbus Division of Police spokesman recommends customers also file a police report as well.

“The integrity of our platform is very important to us,” said an Instacart spokesperson in an emailed statement responding to questions from NBC4 Investigates. “We have comprehensive guardrails in place to make sure that shoppers and customers alike can use and enjoy Instacart safely. Our robust monitoring protocols – such as automated alerts when shoppers manually add goods that exceed the pre-approved amounts – identify abuses of our service and any shopper found to have engaged in fraudulent behavior is immediately suspended from our platform.”