USSD codes for barring

[vagusorbis]

I've turned off the mobile data on my phone, but somehome it seemed to have leaked and costed me data usage. I'm 100% certain that I've never accidentally turned it on, and have been using wifi only.

Is there a USSD code / short code to key in on dialpad to manually bar data usage from the account?

In fact, I'm also looking for a complete list of USSD codes available on O2 but couldn't find any meaningful links.

TIA.

[Cleoriff]

@vagusorbis 

I thought the question was asked and answered here?

https://community.o2.co.uk/t5/My-O2/Data-blocking/m-p/1404584/highlight/true#M10194 

[MI5]

All generic USSD codes should work on O2.
The only specific ones are for account balance / allowances.
Mobile data can only be turned off by calling customer service to request it or by choosing the £5 bundle which doesn't include a data allowance.
If you have a phone with WIFI assist feature, make sure it's turned off.