A Wellington man is warning customers who shop online with Countdown to check their receipts after being overcharged $45.
The customer was charged for an item that was not delivered and only received a refund after noticing it on his receipt and contacting Countdown.
The man - who asked to be anonymous - said the issue could be happening to other customers.
The shopper ordered 17 different items and was charged $171.98 - $156.98 for goods, $14 for delivery and $1 for a bag.
When it was delivered, the packing slip said two lamb legs he ordered, costing $22.90 each, were out of stock, so he only received $108.03 in goods.
But he was charged the extra $45.80 for the lamb which never arrived. Countdown said in some cases customers will need to contact them to get a refund.
"The outcome for customers is, there could be thousands of us out there with funds that are due to us and we are assuming they should just have been given back to us, in-kind and by an automated technical system," the customer told Newshub.
Countdown told Newshub that on this occasion, the customer was refunded but "depending on their bank's processes, a correction can take up to seven days to show in their account".
The customer believes the only reason he got a refund was because he contacted Countdown.
"They are correct, my refund is likely to come through in a few days, however, only because I went back and made them give it back to me," the customer says. "If I didn't they would still have it and be doing nothing about it.
"There has been no email or notification from them of the overcharge or that they are going to do anything about it. I feel like we are getting ripped off on purpose."
Countdown told Newshub that issues like this can happen on "rare occasions".
"In very rare cases, for example, a system issue or manual input error, a customer might be charged for goods they have not received, and in this case, customers can contact our customer care team," a Countdown spokesperson says. "We do try our best to fulfil every order, and if we can’t, our priority is to make sure the inconvenience to our customers is minimal."
But the Wellington-based Countdown shopper believes that customers shouldn't be forced to go back and ask for a refund for something they did not receive.
"When ordering groceries online from Countdown, you are charged immediately for the items you order," the customer told Newshub. "However if Countdown does not provide items in your order, then it is up to the customer to go back to the customer service desk and request a refund.
"I have been shopping online for years and other supermarkets make this an automatic process, so I have just assumed it was an industry practice, if not a vendor obligation."
The customer says there have been times in the past where items weren't provided and he assumed the money would be adjusted or returned - but now he's not so sure and is requesting historical packing slips.
"For me, this could amount to hundreds of dollars over the years."
Countdown told Newshub that once customers place their orders online, they hold the funds until the day of the delivery.
"On the day the order is to be delivered, our team selects everything from the shelves so it is as fresh as possible," a Countdown spokesperson told Newshub. "When the order is ready for delivery, we send a digital packing slip to the customer, and that evening we process the invoice and charge for what was actually supplied."
But in "rare" cases, customers "might be charged for goods they have not received".
"Customers can contact our customer care team, and it will be rectified at our end immediately."