I finally replaced my faithful/reliable old iPhone 4 with a 5 and have had nothing but grief with the process. With lots of help I have managed to transfer my data to the 5S and replicate most of my settings. Unfortunately my voicemail/answerphone service has disappeared. When called, the phone just rings with nothing happening. When I dial 222, the service responds like everything is set up and even tells me I have messages!!! There seems to be lots of information on how to set up a completely new voicemail account on this website, but nothing on how to carry on with an existing one.
I suspect that the problem may be that I am an existing Virgin customer and switched from a sim-only service to a regular contract with this phone.
There are no options for voicemail/answerphone on the phone settings, so I assume it is a Virgin problem, rather than an Apple one - am I right?