Ashokvardhan Purohit, 32, who has an MA degree in banking and finance and was studying to be a lawyer, redirected bogus compensation payments into his own bank account while working at a call centre in South Yorkshire.
He was found guilty of two offences of theft by a jury at Sheffield Crown Court after a week-long trial and jailed for two years.
Purohit, an Indian national who came to the UK in 2003 on a student visa, took on top UK commercial law firm Osborne Clarke Services after applying for a job as a trainee solicitor in June 2007.
He was shocked to find he was not considered for the job because of his immigration status. Purohit then claimed race discrimination at an employment tribunal and won. His victory was upheld by the Employment Appeals Tribunal and means UK law firms must now consider all candidates on merit even if they do not hold a UK work permit.
But Purohit, who obtained his degree from Sheffield Hallam University and was studying law at BBP College when he was arrested, was at the same time rifling the Orange phone company account through his work at the Ventura call centre in Wath-upon-Dearne, near Rotherham.
The court heard he started working as a customer service officer at Ventura in August 2004 and was also studying for a post-graduate diploma in law in Manchester from September 2007.
At Ventura, Purohit worked for the "escalations team" which handled complaints from Orange customers and tried to resolve them. He had the discretion to give "goodwill" credits to customers of up to 100.
Peter Pimm, prosecuting, said he either set up or reactivated two dormant customer accounts, and credits he handed out from Orange would simply be diverted into his own bank account.
He used other staff members' names and security details to make hundreds of payments into the accounts from June 2006 to March 2008.
Initially he gave himself credits in small amounts but it escalated as he became "bolder and more greedy."
When he issued a credit for nearly 5,000 internal checks were made and his thieving came to light. Purohit was then arrested but made no comment during police interviews.
Mr Pimm told the court: "It is quite possible he was not the only person involved, but it was at least in part his own work."
One of the bogus accounts was in the real name of his landlady of the property where he was living at the time, in City Road, Sheffield. Another account was in a fictitious name and more than 52,000 was credited to it.
He even switched bank accounts towards the end of his thieving spree to try and cover his tracks. All the time he was working at Ventura, he was paying his college fees in full.
Purohit, of Vincent Road, Sharrow, Sheffield, was unusually allowed to conduct his own defence from the back of the court instead of the dock.
He told the jury that he did not know who had stolen the money and said other staff had access to customer accounts.
Orange only recovered a small portion of its missing cash and lost more than 59,000.