Lost data before sending

1. What is the problem? Be very detailed.
I was to send the finalised and saved data, but unfortunately the data is deleted unknowingly
2. What app or server are you using and on what device and operating system? Include version numbers.
ODK, Samsung tablet
3. What you have you tried to fix the problem?
Gone to retrieve data on the settings by scan the barcode but still I cannot retrieve the data
4. What steps can we take to reproduce the problem?
Help me retrieve finalised data so that I can send

5. Anything else we should know or have? If you have a test form or screenshots or logs, attach below.
At the moment am a new user and has little knowledge about ODK

Hi @Danga
What version of ODK Collect are you using?

but unfortunately the data is deleted unknowingly

What do you mean by that? Did you do anything or it just happened?
Did you lost everything (blank forms and saved instances)?