It is not just investment scams people should be wary of from a cold call. A telephone call to someone who is elderly or vulnerable can be the equivalent to a door knocking salesman. 

My Grandad was called out of the blue by someone selling mobility scooters. When Grandad relayed the message to us he told us someone had called saying a new Government initiative meant he was entitled to some equipment to help him improve his quality of life at home and that a gentleman would be calling in on him the next day. My Grandad at 94 was savvy enough to tell us and not commit to anything. 

The next day we had assembled my two brothers, mother and father and in Grandad's front room. The front door to the cottage opens straight into the lounge.  The look on the face of the salesman said it all. He knew there would be no sale that day. 

We fired off questions and we had done our homework. Grandad would not be eligible for a grant so if we had not been there would the salesman had persuaded Grandad he needed a scooter when in fact he didn't need or want one? Would he have paid over the odds? The salesman was also unnerved by the journey he had taken to the cottage which had made him 40 minutes late. He had used his Sat Nav which had taken him over the North Downs via some very steep narrow lanes. He was from North London and clearly not used to extreme country lane driving. 

I don't think he will be visiting our little village again anytime soon!