Hi, Reetu Singh
The auto call recorder app saves the recorded phone call records in the internal memory of the device and within auto call record application.
You must know that call recording is just a audio files and hence you can recover call recording with the help of Android Data Recovery software.
You can download the software from here: Recover Deleted Voice/Call Recordings on Android
Important note: For successful recovery stop using your Sony Xperia phone and do not add any new data on it. Because adding new data will overwrite the existing data and you may lose the chances for recovery.