@Elinka_1609 It can take 48 hours for payment to clear O2's account.
You can speak to the Payment Management Team on 0800 902 0217.
The opening times are:
Monday to Friday – 8am to 8pm
Saturday – 8am to 6pm
Sunday – 9am to 6pm
Best chance of getting through is calling at 8 am
Download Skype if you have no other method of calling: Guide: A Guide to Skype