How to unblock number

[Siob]

2 weeks into my new contract my number has been blocked. I think it may be to do with roaming as I work cross border but o2 can’t tell me why, can’t seem to unblock ( or at least the 2 guys I spoke to fir over 2 hours couldn’t  and referred my issue on to someone else?! )

I now have a phone I cannot use. Got no prior warning from O2 re barring. 
Don’t know what to do. Tried online customer support, in person x2. Promised a call back . Hasn’t happened. 

[MI5]

@Siob 

All contact ways here.

Try all Guide: How to find help & contact O2 

Social media is UK based so a good option, although they may need a nudge now and again.