I need a security code, ee mobile phone, I can use it but it

I need a security code
JA: Just to clarify, what device or product are you trying to access?
Customer: ee mobile phone
JA: When were you last able to use your phone?
Customer: I can use it but it keeps asking me for a security code
JA: Have you tried a Factory Reset? This will erase the phone's contents, but the Smartphone Expert can walk you through restoring your photos, contacts and other data from a backup (if you have one).
Customer: its not a smartphone
JA: Anything else you want the Smartphone Expert to know before I connect you?
Customer: I have contacted one of your technicians about 30 mins. ago. I am with plusnet and my landline is down. Plus net have transferred all my calls to EE because it is the only way of my being able to make outgoing calls. I am a 86 year old pensioner and need to be able to make contact with my family. Before the technician could help me his answer disappeared from the screen. Hope you can help.