There two options for you to try recovering the deleted files:-
If your phone is not rooted 1.Connect your smartphone to your PC via USB. I would recommend connecting your microSD card via SD card adapter or memory card reader.
2. Download Recuva. You may also use Coolmuster or Wondershare Dr. Fone .
3. Run Recuva. Select the type of file you want to restore - videos, images or documents. You also have the option to select specific location from which you want to recover the files from.
4. Follow the prompts to complete the recovery.
5. Once recovered, the files should be saved on your PC to avoid conflicts. Check them and then save them on your device.
If your device is rooted
1. Download Undelete. You can download it from http://www.androidpit.com/app/fahrbot.apps.undelete.
2. Select the storage device from which you want to undelete the files
3. Scan the selected device. Scanning will take 2 to 10 minutes depending on your memory size.
4. You will be presented with the list of retrievable files under different tabs.
5. Select the one you want to recover.
6. One recovered, the files return to the position they were deleted from.
Please note that the file recovery programs need the format to be FAT 32 or NTFS. If your system is not recognized, copy all the contents from the memory card to your PC and format the card to FAT32 or NTFS. Then copy the files back to your memory card.