If it were in fact BBM contacts that were wiped, could the OP do a contact restore from the device?
Interestingly enough, I have lost my BBM contacts on more than one occassion when installing a new os. The solution I found was quite simple, but frustrating enough, if you have set DM to backup your device when connected.
1) Open DM
2) Go to Backup/Restore
3) Select Advanced
4) Select the File Button
5) Select Open
6) Find the most recently saved file
7) A list of items backed up will appear on the left. You can select them all to move over, I just select Blackberry Messenger and press the arrows that point right.