O2 won't let me log in

[Mattshinn1991]

I have done an over the phone upgrade and clicked on the link to accept terms and conditions but my o2 tells me my personal details are linked to another account so I cannot log in

[Bambino · Accepted solution]

@Mattshinn1991 You need to speak to customer service.
Call 202 from your mobile or 0800 032 1402 from any phone or numbers in this link: Guide: Coronavirus Community Help and Support 
When it comes to the reason you are calling, stay silent for 15 seconds and you will be taken to the keypad options.
Press 2 for Everything Else
Press 5 for More Options
Press 7 for Anything Else which will put you though to someone.
Say 'Upgrade', 'Lost/Stolen', or 'Fraud' if the suggestion above doesn't get you through.
Best time to call is 8 am.