I'm afraid that I can't help with regard to a three digit PIN.
However you can set your phone up by selecting the make and model from the list HERE
Alternatively, give the team a call on 789 from your Virgin handset or 0345 6000 789 from any other phone.
If you want to say thanks > click 'Kudos'.Answered your question? > click 'Mark as Helpful Answer' also.