The unnamed ex-worker has hit out at the world-famous retail brand, accusing Amazon of routinely sacking its employees at the warehouse for not meeting "unrealistic targets".
He told Newyddion 9: "Things like timed breaks, constantly monitoring you ... Not being able to have the freedom to go to the toilet without someone coming and being like, 'right, you've been five minutes away from your task now, what have you being doing?'
"You are essentially a robot trying to get everything 100 percent perfect, and if you don't meet those standards then you know about it.
"I'd say they treat you like a number and they treat you like robots, and after a while, because of the brain-numbing work, you become a little bit of a robot as well.
"When it got closer to Christmas there were people getting let go every week. I saw people getting sacked around me, they'd get asked to meet their line manager and I wouldn't see them again.
"You were very aware that you were part of an expendable workforce."
However, Nick Fyfe, Amazon's regional operations director, has defended the company's approach.
He said: "I welcome scrutiny, I think that's an important part of what we do, but I do not recognise the stories that I see in the press."