While rare, it's not unheard of for a "spontaneous wipe" of user data and such to occur. Hence the importance of conducting regular backups, for the device itself is a mere commodity, while the data on it can be quite priceless.
On the device, there is no recovery hope -- once deleted on a BB, gone forever from the BB. Recovery depends now on a separate source of data. If you've availed yourself of any of the free methods that BlackBerry provides, then you would proceed to restore from that.
If, however, you've not availed yourself of those, then this old saying would apply -- "There are two kinds of computing device users: those who have lost data, and those who will". Backups, like insurance, are neither a reactive nor an optional activity.
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.