Despite the 'other' response whom it would appear did not understand the question - there are several such companies, but Tata/TCS are not one of them. Many are small so it will take time finding them, it could also depend on where you live etc. You can start with a Google search, call centre mags will also provide info. You can try Blue Sky, the Call Centre Focus mag has a list in the back. Although if you are already working in this space then I would have thought you would have seen these?Hope this helps