Asda’s billionaire bosses forged ahead with a botched IT transition despite being warned in advance that thousands of workers would be paid incorrectly, The Telegraph can reveal. Senior figures were told in advance of the problems underlying the changeover, which has impacted 30,000 employees and left some hundreds of pounds out of pocket.The IT changeover is being overseen by the company’s billionaire co-owner Mohsin Issa, who has made clear it is one of his top priorities. The crisis has led to calls from unions for Mr Issa to apologise. The revelation that he was warned about issues with payroll ahead of the transition are likely to only heighten pressure on the billionaire tycoon. Problems relating to the payroll first arose last month. Asda has been unable to fix the issue since. The ongoing payroll crisis at Britain’s fourth-largest supermarket led to further problems on payday last week, with internal systems inundated with complaints. Some employees were underpaid while others were overpaid. Financial pressures led to store managers making £200 petty cash payments to affected staff last month, although it is understood this will not be the case this time around. A senior employee at Asda said there had been “thousands...