Rama Vrambhia, who runs Snutch Newsagents in Leicester with husband Subhash, wants to make other retailers wary of trusting the machine to get it right.

She says: “The rep said it’s all Chip and Pin so you do not need to keep a record or balance; the machine does it for you. But I do keep a record. It was £4.29 out. I called Worldpay and they said it was a declined payment but I knew I had the paperwork to show it went through. So Worldpay said okay we’ll give you that one as a goodwill gesture.”

She told the rep that even though the machine says ‘Pin verified’, it doesn’t mean that the money would be in her account. “The rep said okay I’ll come and have a cup of tea with you. Well, I didn’t want a cup of tea. I want to make people aware. Even if Chip and Pin is verified there is a possibility that it is not – do an end of day balance.”