Slight misunderstanding, I've got service but my contacts reformat from time to time as mentioned, Whilst changing settings to restore the correct format I noticed the Sim Application option was not there, it was last July and October because changing from Manual / National to Manual /International is the only way to get roaming service abroad. Here is a reply from Gareth_L regarding using Sim application -
If you’re using an Android phone, please can you do the following: Selects Apps from your home screen > Virgin SIM toolkit > Roaming > Mode > Manual > International. Once this has been done you might need to reboot.
If you’re using an iPhone, please can you do the following: Settings > Phone > SIM Applications > Roaming > Mode > Manual > International. If you’re using a newer iOS, then you it will be under Mobile Data instead of phone. Once this has been done you might need to reboot.