There may not be many options to recover Nokia phones, but there are things you can try

You can download Recuva and plug the phone in with USB and do a deep scan, see if it sees everything on the phone and can be recovered, this will probably be your best bet

http://www.piriform.com/recuva

It's only for PC's, so you will need access to a PC with at least XP long enough to do it

If Recuva does not work, try to find a tool specially wrote to recover data on this phone, I don't want to recommend any particular utility that was written for phones, for the simple reason some will work and some won't

If the lost data is saved in the internal memory of the phone, I think you have to reflash the phone system. But if the data you lost are saved in the SD card of your phone, it is possible to recover them by some recovery tool,

The First Thing You must remember: Stop transferring immediately and don't put any new data into the card. Just keep it in the place of its own, because lost data will be overwrite by the new files, which will decrease the rate of mobile phone data recovery.