applied to pretty much every job agency when i got out of uni, and i only got offered any employment from a grand total of two of them - once i'd found near-full time work off my own back a couple months earlier. as far as i could tell, i was vastly over qualified for anything they had to offer (i had GCSEs and could type at more than 20 characters per minute) even though most people in their office had trouble reading the adverts in the window but were walking into all kinds of employment.
mind you that's actually unfair and just bitter
most of the time when i chat to those callcentre folks they're spot on. sometimes having to grudgingly work to a script or needing to try and trick you into stuff in order to get enough commission that they can eat AND drink clean water the next month, but awake and intelligent all the same.
(not always, though... there's the odd goon who has trouble with 2+2... as ever, it's not that they only take idiots - it's that they take everyone desperate enough for work that they'll bother to apply, and you have to play the call queue lottery)