Backup lost contacts on android?

[MorrisJ]

Is it possible, what software shouls I use?

[SiliciaJay]

I had the similar issue and I use disk drill. There is a detailed instruction https://www.cleverfiles.com/apple-data-recovery.html . At first scan your device and then restore the deleted files. It's done:)

[SiliciaJay]

or use your gmail account to recover them

[Masderndf]

Anciently , people can scan their phone device for contacts recovery , this kind of practice is very popular and effective ,
See more : http://www.android-rescuer.com/recover-contacts-from-android-phone.html