Mobile phone giant Vodafone is to close a newly acquired subsidiary with the loss of 480 jobs.
Cellular Operations, in Swindon, was bought by Vodafone in March.
At the time, staff say bosses promised there would be no redundancies and it would be business as usual.
In a statement, the company said some jobs would go in October, and the rest by the end of the year.
A Vodafone spokeswoman said no assurances on jobs were given to staff in March.
Clearly, they would rather spend all of their money on expensive advertisements with David Beckham
Cellular Operations staff member
"At the time we hoped we might be able to keep it open.
"The review has shown that there is definitely no hope of that," she told BBC News Online.
There was already enough capacity within existing Vodafone call centres to make the Swindon site surplus to requirements, she added.
Staff at Swindon were angry at Vodafone's decision to pull the plug on the company.
"I think we were given false hope and Vodafone have pulled the rug from under us," one staff member told BBC News Online.
"A lot of people are annoyed, because for the last two years we have been service provider of the year - and that is for the people who work here, not the company.
"We have worked hard to get where we are, and now Vodafone has just left us.
"Clearly, they would rather spend all of their money on expensive advertisements with David Beckham.
"I like David Beckham, but I would rather have my job at the end of the day."
Cellular Operations provides mobile service packages for large corporate customers, including Ford, Jaguar, Trafficmaster, and the RAC.
One of the main reasons for buying the business, a spokeswoman said, was to gain access to Cellular Operations' customer base.
The 360,000 Cellular Operations customers who currently use Vodafone services will now have their accounts managed by Vodafone as well.
A special call centre providing advice for the elderly and disabled, which is part of the Swindon site, will not be affected by Wednesday's announcement.
Vodafone said it was unique within the group and efforts would be made to keep it in Swindon.