How can you assure people contacting you aren't fraudsters?
A few years ago I had been to St Petersburg (pre conflict)
As I landed and was collecting luggage I had a call from my bank asking me if I'd been away and they were from the fraud team. I was really worried I was being scammed and really flustered. They asked where I'd been and what I spent and if I had been to Florida and spent in car park?
Anyway it seems it was genuine and perhaps my card had been cloned in Russia. They refunded me and cancelled the card
Another one was Amazon an email asking if I had attempted to log in ( it was my husband but didn't realise).
If someone rang me tomorrow there is no way I'd believe them. How can you verify this?