I have an iPhone 5S and I've just noticed if someone rings my number it rings about 15 times but instead of going to voicemail it gives the following message 'the mobile number that you have called is currently unavailable please try again later. I have reset all of the phone settings to no avail. I have set up the voicemail to give the default reply should it not answer the phone. Can any one advise please ?
Thanks.
John
