Technical messed up my ipod

Today I went to the istore Clearwater mall. Booked a technical app for 16:00. My laptop updated to windows 10 and my ipod and ipad updated to latest software. So my devices weren't being recognised by iTunes. The technical guy that helped had a black shirt on. So the senior of technicians. He managed to sort my ipad out. But he seemed to have damaged my ipod. Only saw this when I got home. He formatted my ipod on his laptop. And then on mine. re-downloaded the software on his laptop. Still same message on iTunes and laptop wanting to format the ipod. Now when I got home the ipod has a lock in the left top and a tick in the centre saying OK to disconnect. I can't switch it off. Can't get onto it either. :( The guy was helpful with my ipad but with my ipod left me standing there an hour while chatting to other customer, then I ask is mine busy has it shown it is working can we plug it in. pulls it out of my laptop without ejecting it safely. now it is not working can't go onto it. it is just a lit screen with a lock and OK to disconnect. iStore I want this ipod sorted out or a new one given to me. It still played my music before I took it to your technicians. now I can't put new music or play music or even get onto the main screen or turn it off and on again... :(