Banned From Trading in

Can anyone that works or worked at eb games please explain to me.

A few years ago I was trying to get rid of my console collection. I traded in multiple consoles but then got rejected and banned from trading in? Why is this? Also they said they don’t know how long for am I banned forever? Im trying to trade in a switch oled tomorrow but not sure what will happen. Im just trying to get a little bit of cash cos things are tight at the moment. The worst they can do is just refuse correct?