Sepivip, these are volunteer forums. If you don't get a response quickly it may be because only a few people have the answer and they don't log in that often to read posts.
If you don't get a response at all it may be because no one knows the answer.
I'd think that you probably need an experienced administrator to log in, to look at the file structure of the underlying drives. How did you create the RAID? What level of RAID? Did you configure the RAID to use ext3? Did you format it before you loaded files on it?
Were there files on one or more of the drives before you created the RAID? You can't do that with most RAID levels.
Where were the missing files? On the original drives or the new RAID set? If on the original drives, then of course mounting something at that point will make them disappear.
There are still many questions here; this may be something you need an experienced administrator to look at using various RAID tools as well as fdisk.
Jeff