My landline phone (BT 6500 Cordless Phone) rings if you have hung up but if the person on the other line hasn't hung up after 5-10 seconds which is great if you accidently turned off the phone (my parents do this all the time) and in this instance for this case.
(https://news.ycombinator.com/item?id=4825751)
(https://news.ycombinator.com/item?id=4826367)
Here's another newspaper article about the scam. (http://www.guardian.co.uk/money/2012/may/23/credit-card-user...)
EDIT: cultural note - we don't[1] pay to receive a phone call, even with cell phones. Perhaps that makes a difference?
[1] Well, with normal accounts that is. Obviously free-phone 0800 numbers etc are different.