Who do I contact to have my portable phone repaired?

Cosmetically, the police box exterior of the TARDIS has remained virtually unchanged, although there have been slight modifications over the years. For example, the sign on the door concealing the police telephone has changed from black letters on a white background to white on black and white on blue at various times. Other modifications include the continual jumping back and forth of wording on the phone panel from reading "Urgent Calls" to "All Calls". The "POLICE BOX" sign was wider from Season 18 onwards and for the 2005 series, but not for the television movie. Early in the programme the TARDIS also had a St John Ambulance badge on the main doors, but this eventually disappeared. The Empty Child revealed that the exterior telephone is non-functional because it is not hooked up to any telephone lines.