Wendy Clements helped herself to almost £460,000 from ASDA and was only caught when someone noticed "large amounts of cash just lying around" her home.
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Clements, who worked in the cash office, managed to steal the incredible amount over a period of four years by fiddling the amounts recorded on tills in the petrol kiosk.
She splashed the cash, stolen from ASDA in South Bank, North Yorkshire, on holidays and meals out.
Now, the 47-year-old from Middlesbrough, has been jailed after fiddling the petrol kiosk's tills at the store, benefiting to the tune of £459,925.
Ian West, prosecuting, said Clements had worked out that the electronic records on the tills were not linked to the "smart record" that she would submit to ASDA's head office .
So she understated the amount of cash taken at the till and simply pocketed the rest, the Gazette reported.
Mr West said: "Over the period, she took over £450,000 in cash. The system of recording cash takings has changed since.
Despite the huge sum stolen by Clements, Mr West said she "literally blew the lot" on holidays for herself and family, meals out and even cosmetic surgery for someone else.
"It was basically living the high life - money was spent like water," he said.
With no cash left, police and prosecutors ruled out trying to claim back compensation from Clements and said that ASDA would have to pursue a civil claim to recoup any of the money.
John Nixon, defending, said Clements was "a lady of very low self-esteem" who had suffered depression after the break-up of her marriage in 2012.
Mr Nixon said: "She found herself unloved and unwanted. In her own words, she began to buy people's affection."
Regarding ASDA's accounting system, Mr Nixon added: "It may well be, that with better systems she would never have found herself in front of this court."
But Judge Stephen Ashurst disagreed. He said: "I'm not sure I buy that. She's been smart enough to identify the loophole in the system. She not only noticed it, but exploited it."
Mr Nixon added that his client had showed genuine remorse about the harm she had caused to her co-workers, and felt "great shame."
Describing the "vast scale" of Clement's theft, between January 2012 and February 2016, Judge Ashurst continued: "This was £150,000 on average a year. The motivation here is greed - nothing more, nothing less.
"The most troubling aspect in this case is the traumatic effect your offending has had on three innocent women. Between February and July last year they went to hell and back.
"You could have averted their acute distress by having the honesty to admit it when you were arrested. In my judgement that was a wicked thing to do."
He jailed Clements, of Middlesbrough, for three years and four months at Teeside Crown Court after she pleaded guilty to theft and falsifying accounts.
ASDA has been approached for comment.