Vodafone complaint

Helpneeded456

I sent a complaint to Vodafone regarding a debt that they say is my sons dating back to 2015 - which has now gone to a CCJ he has had no communication with Vodafone prior to finding out that he has a CCJ.
My son is a vulnerable adult with mental health issues, depression and severe anxiety and  this debt that he had no knowledge of until very recently is having a severe impact on his mental health. He has given permission for me to communicate with Vodafone on his behalf.
I sent a complaint to Vodafone on 19th January (it says I should receive a response in 7 - 10 days) so far I have heard nothing from them.
How can he prove the debt is not his ? Surely it is Vodafone who needs to prove it is his debt? He cannot answer any of the questions regarding the security checks - because he never opened the account - but they are insisting it is his debt - surely this cannot be correct? 
Can anyone offer any advice? Who do I contact next? We have tried CIAS- but they dont deal with possible fraud cases.

PHK

It's impossible for a CCJ to be issued without the court papers at least being delivered. Is it possible he has been overlooking communications? 

You need specialist advice here, so I would start by contacting Citizens Advice. 

Helpneeded456

We think the papers were delivered to his old address -