I have 2 phones with o2. One of which whenever I go abroad (doesn't matter on location) my phone data never works... Whats app/facebook/emails (anything really)
The only way of gaining access to the above things is to sign on to Wifi or connect as a hot spot to my other phone??
1 - Reboot phone.
2 - Manually search for a different network
3 - If using an iPhone, change data apn to "mobile.o2.co.uk"
4 - Check with O2 for any roaming bars.
If you message O2 on Facebook (https://o2uk.co/O2CFB) , Twitter (https://o2uk.co/O2CTW) or Instagram (https://o2uk.co/O2CIG) , they should be able to help you with this.