Once Jailbroken grab iFile from Cydia
Upon opening iFIle you will see a list of directories where all things that make your iphone an iphone live...
It's just like a PC/Mac directory structure Tap on the folder name to go into that directory and if you make a mistake tap the folder name in the top left corner.
You need to navigate to System > Library > Carrier Bundles > iPhone > Scroll down a fair way until you see "O2_UK.bundle" > Tap that (not the blue arrow at the end which just shows the properties of it.) then you will see a list of files
One is called Carrier.plist, Tap it and you will be presented with a list of options with which to open the file.
Choose Property List Viewer
Scroll to near the bottom of the opened file and you will see a field called "VoicemailPilotNumber" which will have a value of 901
Tap that, edit the number to 443 (dont hit return or add any spaces or anything else after the 443)
Press on carrier.plist (top left)
Tap Done (top right)
That's it! Almost, power off (hold down power button and 'Slide to Power off' wait a few seconds and power your phone back on (a respring isnt enough for those that know what a respring is and if you don't then just switch it off and on again)
Tap the phone icon, Tap the Voicemail option - sorted it now dials 443..
Upon opening iFIle you will see a list of directories where all things that make your iphone an iphone live...
It's just like a PC/Mac directory structure Tap on the folder name to go into that directory and if you make a mistake tap the folder name in the top left corner.
You need to navigate to System > Library > Carrier Bundles > iPhone > Scroll down a fair way until you see "O2_UK.bundle" > Tap that (not the blue arrow at the end which just shows the properties of it.) then you will see a list of files
One is called Carrier.plist, Tap it and you will be presented with a list of options with which to open the file.
Choose Property List Viewer
Scroll to near the bottom of the opened file and you will see a field called "VoicemailPilotNumber" which will have a value of 901
Tap that, edit the number to 443 (dont hit return or add any spaces or anything else after the 443)
Press on carrier.plist (top left)
Tap Done (top right)
That's it! Almost, power off (hold down power button and 'Slide to Power off' wait a few seconds and power your phone back on (a respring isnt enough for those that know what a respring is and if you don't then just switch it off and on again)
Tap the phone icon, Tap the Voicemail option - sorted it now dials 443..