got call from embassy after visa approval

[whatsnow]

I had my visa interview on 13th and officer said my visa is approved, they keep my passport.

on 14th I received call from embassy asking who is my employer and my I-797 number,

since I am out and I dont have my I-797 number they said they will give me call back on monday.

 

did anyone experience such scenario before ? why they gave me call after my visa approval ?

 

here is my interview questions

 

greetings were exchanged

 

VO : which company you work for ?

Me : XXXX (MNC company)

VO : is it your petitioner or client ?

Me : both

VO : how much you is your salary ?

Me : XXX

 

typed some time and said your visa is approved.