My phone is disconnected so I can't get verification code

[dalyer]

If you mean for porting your number from your old network to 48 then see here: 

• https://community.48.ie/t5/The-Knowledge-Base/Getting-Started-Moving-Your-Number/ta-p/53100

If your old network SIM has no service or you can't receive the security code SMS, then you will need to make contactw with your old provider as they will have visibility of your old account. 

So you need to contact your old network about this.

If it's to do with something other than number porting then you'll need to explain the issue in more detail and more clearly.