Cloud services

So I'm currently in the process of our fourth or fifth great Dropbox recovery with a work project. I'm fed up, and so is my boss, so we're looking for a better solution. Basically, the issue is Dropbox's lack of read/write permissions. A user will move a file from a shared folder, not realizing this registers as a deletion for Dropbox, and suddenly we're short massive amounts of files and I get a dozen panicked phone calls from luddites who don't understand file recovery.

What I really need is a cloud storage option that provides read/write permission so that I can keep people from deleting files, or at the very least one that doesn't delete from the server when a file is moved. Do any of the services out there provide something like that, or any way to fix my problem?

It's not just that. Yes, people do occasionally delete things without meaning to, but that's easy to fix when it isn't "oops, I accidentally the everything". In this latest instance, I really do think it was a bug with Dropbox. About a thousand files are missing from 55 random folders and subfolders, and isn't entire folders that were destroyed. It's like Dropbox just wigged out.

If they had reasonable tech support this would be no big deal, but there's no tool to do mass recovery on my own. It has to be done by hand with no recursion. There needs to just be an "undo" button on the events page. I can't even get someone on the phone because they refuse to do phone support. It's an email ticket only, they don't even send me a confirmation that the ticket was received, and the turnaround time is 1 to 3 days. That's just awful, especially when the web is littered with Dropbox horror stories.

I'm going to start testing Bittorrent Sync for myself, and see if it's viable. It's probably too complicated, but we need something else.

It's largely office files. Word docs, Powerpoint, and a fairly sizable number of spreadsheets that contain a lot of our data on project participants. It's mainly a collaborative tool so that everything is in one place. If people would refrain from using the Explorer plugin it would help a lot, as that seems to cause the most problems. The web interface takes a little more effort to fuck up, and the plugin seems to be glitchy.

Read-only access would be nice, but what I really need is user level sharing options so that I can flag certain users as unable to delete files.