"so the overload was passed to BT's RIDE call-handling system"
Hmmm, its not as simple as that. BT didn't just properly "handle the call as an overload" which would have involved giving the caller an ENGAGED tone and the caller not being charged for the call.
No, BT implemented a system which ensured that the customer heard the exact same message as they would have heard had they been connected. And they implemented a system for levying a bogus charge on a call that should have been completely free of charge (to the caller, at least -- they could possibly justify charging the network operator for providing the facility).
It must surely have been obvious to BT that they were aiding and abetting a fraud in this manner ?
And neither ICSTIS or Oftel has noticed their part in the procedings ?
In respect of the deceit through overflow calls, BT is far more the guilty party than the others accused and Oftel at least should be laying down the rule that overflow calls should get either a busy tone or a an announcement that makes it clear that the service was not reached and that the call was not charged.
Anything else is surely FRAUD and by failing to spot it and stamp it out, even Ofcom is surely aiding and abetting a fraud.???
Overload calls need to be FREE to the caller and Ofcom must do its job and ensure that happens in future.