I was on a contract team which setup one of the rooms in the Bolton centre a couple of years ago. I've seen some bad call centres, worked in a few, but the environment there was easily the worst.
Untrained staff, mainly asian origin with minimal language skills being treated as near-slaves. The management attitude worked down to the front line staff, who in turn treated the customers like shit.
Bullying of staff, limited loo breaks, impossible call rates, IT support staff who were prevented from fixing things for budgetary reasons (i.e. no spare keyboards or mice). 60% of the light tubes were faulty - and requests to fix them were refused on cost grounds, despite the illumination breaking HSE regulations.
Once the PCs in the room we set up were installed, I was glad to be away from there.
The key thing is that the site was contractor-run, not a part of the civil service. It was expanded while DWP sites such as Norcross and Piel Park were being closed. Who ran it? United Utilities.