grandmother scammed out of 50.000 $ and she won't listen!!

Hi, I joined just to message you. My grandmother lives in new York, we live in the UK, this is currently happening to my 86 year old grandma. She has given almost 50,000 dollars to a bunch of scammers but won't listen. They are ringing her to say she is entitled to just over 1 and a half million but must pay charges and tax to obtain said money. This has been going on for over a year. $1000 here $3000 there be living she will receive her money soon. They said a man would drop off the check if she paid 1000, she did, on coming over with the cheque he died in a car crash, a woman rang up crying explains that this 'man' had died and my grandmother sent a bereavement card. She then received a phone call from the "irs" claiming that they can see she has all this money and why is she not paying tax, if she doesn't pay tax asap the police will be round. For an elderly person to be hounded like this is absolutely heartbreaking. We just live too far away to make an impact.