US credit card company Capital One has torn up its contract with Indian call centre company Wipro Spectramind.
Capital One in Indian call centre row
Action was taken after Capital One found out that Wipro staff had made unauthorised credit offers, gifts and club membership to customers.
"Certain activities were not up to our standards" said a spokeswoman for Capital One.
Angry staff at Amicus, the finance sector union, are calling for an investigation into the case.
Wipro, based in New Delhi, is India's largest call centre. Staff were extending the terms of special deals beyond their end dates and offering levels of credit more than would normally be allowed.
Around 600 staff worked on the Capital One account, one of the biggest for the company. So far 30 employees have been sacked, Reuters report.
Offshoring under scrutiny
Capital One denies that it will pull out of India altogether. It confirmed that extensive investigations had confirmed that the issue was limited to several individuals at a single site.
Other firms, however have taken some work away from India, including UK based football pools company Littlewoods, computer manufacturer Dell in Texas and investment bank Lehman Brothers.
Customers need not worry as this matter, Capital says, did not involved compromised customer data.
Several unions are calling for action and have launched an independent commission of enquiry into offshore call centres. They want the UK Government and European Union to force offshoring companies to disclose the country they are calling from.