I have been charged multiple times

[Viki1]

hello I have been charged multiple times on my card , I usually do monthly tarrif and I have recently changed my card , it didn't charge me so I had to top up but I still didn't get my tarroff , so now I have £30 on my account balance and I managed to get my tarrif but why has it charged me on the account balance £30 , so I have nearly spend 50 pounds ,I want to cancel the account balance 

[TallTrees]

Hello @Viki1 

Welcome to the O2 community We don't have access to accounts so you need to contact o2 customer services Here 

Guide: How to find help & contact O2 

Payment management may be useful here

You can reach 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
https://www.o2.co.uk/help/account-and-billing/payment-support
Best time to call is around 8.00am