Charges abroad

[Batfink2009]

Hello

I purchased a dual sim from Mobi matters which I have been using whilst in America. I would therfore like to know how o2 have charged me travel bolt ons equating to £30 for this billing period?

I have also looking at my online account been charged £6 today already by o2 when I am still in the hotel and on their WiFi plus on my other sim from mobi matters?? 

How is this possible? 

[Enlli · Accepted solution]

A number of reasons as to why this has happened.

The main one to cause this is the failure to disable voicemail BEFORE leaving. 

When a call is not answered or your phone is unavailable then that call is diverted back to your voicemail in the UK. This would trigger the £6 as any use will do this.

[jonsie]

 also need to disable mobile data for the O2 sim