CeX / WeBuy.com review: warranty

I was today at cex Ilford to see what happened with my hp elitedesk 800 mini G2 that I bought 10 days ago, the desktop machine was not powerin on anymore, the till girls were really nice and told me to come back after 40 minutes, instead I waited there in the shop and the guy that was doing the warranty checks treated me disrespectfuly making funny voices against me, the experience was really awful.