Just a heads up.
My elderly parents almost got taken in.
They ring saying they are for a government department and the have found the banks have overcharged you through bank fees by thousands.
They give you a phone to ring back and talk to there manager to prove they are legit (yeah right)
Than tell you to go to the post office to get a form and ring them and they will help fill it out. They also ask bank details or cash up front.