A while back The Community Magazine Focus gave warning of attempted fraud on Bank Accounts, using the ring back technique.

Someone just tried the scam on me, and received very short thrift. If my later attempt to contact my bank is anything to go by, phoning them is an impossibility. Even a through number provided took me to the Tesco Mobile Messaging Service.That might be helpful for those who bank at Tesco's.

One begins to worry about the reliability of Banks in general.