In what way is your roaming passport "not working"? It's a billing add-on whose purpose is to reduce the cost of roaming.
I suspect you mean that your phone doesn't have coverage abroad, in which case the billing add-on has nothing to do with it. Regardless of any billing add-on, your ability to get coverage abroad (which calls, texts & mobile data rely on) is dependent on roaming being activated - which allows your phone to connect to foreign networks.
On pay-monthly, this needs to be enabled manually - usually by texting ROAMING to 150 before leaving the UK. Did you do this?
If you now find yourself abroad without having enabled roaming, your only recourse will be to contact CS to request it activated. You can either contact +44 7953 966150 from another working phone, or +44 800 0798586 using a web-calling app such as Skype over WiFi.
If you explain to the CS agent that you have forgotten your security password, they can ask you alternative questions to verify your identity and proceed with the call.
