The manager of Exeter's All Saints store turned all sinner when he found a way to swindle £100,000 by issuing bogus gift tokens.
Christopher Phillips lavished presents on his fiancée and planned a luxury wedding in Mexico with the profits from the fiddle in which he was adding thousands of pounds a week to his salary.
The 38-year-old was processing a genuine refund for a customer when he accidentally unplugged the machine half way through a transaction.
He discovered he could issue a gift voucher for up to £450 without it registering on the company's system and went on to exploit the loophole by returning the same leather jacket over and over again.
His swindle netted him vouchers worth £104,950 in the space of 20 months and he used them to buy clothes and jewellery for his bride to be.
He took other items home to sell on eBay and by the time his fraud was detected he was printing five vouchers a day.
The scale of the fraud alerted the company's accountants and he was found with almost £30,000 worth of gift vouchers which he had not got round to using.
He admitted the swindle and told them:"Look, I got greedy. I did it because I could. I learned how to do it by mistake."
Father of two Phillips, of River Plate Road, Exeter, admitted fraud and was jailed for two years by Judge Phillip Wassall at Exeter Crown Court.
The Judge told him:"You were a manager when you stumbled across this way of committing fraud and on a great many occasions, something over 50, you created the credits which you used to get clothes in return.
"You sold some on eBay to fund your extravagant lifestyle. You were the store manager in a position of high responsibility and trust.
"The breach of trust was so great and this fraud was so long and protracted that there must be an immediate prison sentence."
Mr Gordon Richings, prosecuting, said Phillips was found with 67 vouchers worth £28,213 when arrested and had already cashed a further £76,736.
He said:"He told officers he committed the fraud to maintain his lifestyle and bought items of clothing and jewellery with the vouchers for himself and his girlfriend and he was due to marry in Mexico the next month."
Mr David Evans, defending, said:"He told me 'I am totally in the wrong and deserve whatever I get. He has ruined it all."
He said he only wed five weeks ago to his long term girlfriend and mother of his two sons, with her family paying for the wedding in Mexico.
He said:"It had become an obsession. He is the author of his own downfall. He discovered this technique by accident when the power went off."
He said Phillips wanted to pay off the outstanding £76,736 in £40 a month installments even though it would take him 38 years.
