I am not able to call or receive any calls or messages today

[Meheranghiz]

I haven't received any calls or messages including voice message today nor am I been able to make any calls or messages in UK or on WhatsApp.

[Enlli]

As WhatsApp uses data to send messages and calls I would suggestvyou have a look at these guides first

Guide: Is the network down for me or everyone? 

Guide: How can I sort out my network issues? 

[Meheranghiz]

I need to talk to one of your agents re the service. Can you provide a contact number?

[Bambino]

@Meheranghiz See this: How to find help & contact O2: A Guide - O2 Community