Rear cupholder won't retract in E220

[Margaret]

Hi all. Am embarrassed to ask this but I cannot for the life of me manage to retract the rear double cupholder in my nearly new E 220. I think the sliding mechanism could be stuck. It means i am unable to fold up the armrest as the cupholder is sticking out ! very annoying ! I have looked at the owners manual on the disc supplied and I think the pictures look like a different type to mine. It was open when i collected it and im wondering was it already broken as its a demo model. Has this happened to anyone else. Can anyone advise ?