I worked on the business continuity plan for a major call centre. During the process I was staggered to find that the UK is littered with fully functioning, but vacant call centres. Desks, PC's the lot... People throw a lot of money at this.
The problem is that somewhere between the customer and the call centre there needs to be a switch which switches the customers call to whichever of your many redundant call centres is being used. It doesn't matter how many call centres you have if that switch is the bit that goes wrong.