If your deleted files were stored in the phone memory or memory card instead of SIM card, then it's possible and quite easy to retrieve them. The best way is by using some recovery programs such as Wondershare Data Recovery. But before your deleted files are retrieved please don't save more files to the phone in case rewrite original file data.
Here is the steps you may need while using
Wondershare Data Recovery,
1. Download and install the
data recovery tool on your computer. It's free download.
2. Connect your phone to the computer. Open the application, and then select the partition or directory that files deleted or data lost, and then click Next to start data recovery.
3. After a while you will find a lot of files found listed in the list box. Select the files that you want to recover, and then click Next to continue data recovery.
4 Select Path for Recovered Deleted Files.