Hoping someone can answer this as it may save a load of time trying to discover the problem.
I can call my mobile from a fixed line and it is ok. The garage called me earlier today, got through no problem.
I call my mobile from my woman's mobile, in a short time on her mobile screen it says some rot about conditional forwarding being active. Then the call drops.
'Conditional call forwarding' means that a call will be diverted to voicemail if it can't be taken immediately. (e.g. if the person is on another call).