It is possible to recover deleted files from Nokia phone with data recovery program. However, if the files has been overwritten by other files, then the deleted files are not recoverable. But you do not know whether the files are recoverable until you run the data recovery program to try to recover the files. I came across a Nokia phone data recovery recently:
You can follow the step by step guide and try to recover the files, if failed, then means files are overwritten and not recoverable. Otherwise enjoy the recovered files.