The scam call exists but there are also some genuine ones.
I once received a call from a private number
She told me her name and said she was call from immigration office. On a Sunday

She asked if I am doing health care job now and I said NO. I was suspicious but remained polite.
I then asked why she called she said she was doing her job to know if started a new job because many people went into health care.
She did not ask for any other information.
She called on Sunday, Monday was Easter-Monday and I received AIP on Tuesday morning.
I believe that was my first stage Angel who sent my AIP.
My advice is, be polite with them without releasing any sensitiv information if you are not sure.