Thanks - I did try that but my operator (the 'Three/Vodafone' network in UK) doesn't support the action No. 2 (Disable call forwarding to voicemail on busy event).
I have set Callfilter.app to block all calls from numbers not in my contacts, and used the wildcard in my whitelist to allow calls...
I have seen this problem raised already but the solutions do not work for me.
Unless I can get the otherwise excellent CallFilter to deny blocked calls access to voicemail I will have to give it up.
I would like to understand why it happens anyway? Does CF not simply terminate blocked calls?
At...