Stolen phone and can’t contact o2

[Snow]

Hello, I am in Vietnam and my phone was stolen. 
I want to report this as stolen and the o2 chat bot has given me a number to call for when you’re abroad. I have attempted to call this number from my boyfriends phone but it is giving and error message in Vietnamese. 
I have added the correct international extension +44 but this is still not working. Do you have any guidance on how else I can contact the o2 team to inform them the phone is stolen? 

thanks in advance 

[madasaf1sh]

@Snow 

Use Skype ( Guide: A Guide to Skype ) and call o2 on +44 800 902 0217  or from a mobile  +44 7860 980 202 if the details in this guide dont work Guide: Lost or Stolen O2 Device? - How to Report it 

If the error is in Vietnamese it means the local network doesnt recognise the UK number especially if trying the  0845 number  or the short codes (not all foreign networks recognise non-geographic numbers)