MrsBB1982
Ok, well from your second post, i think it you have two choices really to either sit down and have a long talk with both his key worker and the manager, maybe do some more settling in sessions with him where you stay together for an hour (is that possible, or will they let you) if you do have a meeting, make sure you write a list of concerns/ideas so you don't forget to mention anything.
Does he eat and sleep at nursery? if he does i would take this as a positive sign, most children who do this even if they cry all day will eventually settle, i know that sounds horrible, but those two things tend to be the hardest hurdles the climb over.
Could you let him take a comforter (dummy, teddy, muslin, toy), or something that smells of you, i often advise parents to sleep with a muslin, or walk around with one down their tops, and then we use that to help comfort are distressed babies.
Does he like being with other babies, do you socialise him outside of nursery? and before he started? If he doesn't maybe you could take him to some classes with you that he feels secure but it will build up his confidence.
I would def suggest to them things he likes doing at home and also maybe ask if his key worker can be changed, let them know he likes engaging with people and toys and not left to his own devices, he may need encouragement to do x,y or z.
Or you pull him out, and find somewhere else to go? Maybe a childminder with a more homely feel?