Unwanted subscription charges for "O2 Unlimited Games Flatrate"

Hello, 
I am an O2 contract customer (Kundennummer: xxxxxxxxx). On my latest bill from 02.09.2026 for the phone number xxxxxxxxxxx, I was charged 12.99 € for "O2 Unlimited Games Flatrate". 

I never subscribed to this service, never used it, and never authorized this charge. I have already activated the Drittanbietersperre (third-party provider bar) in my account settings to prevent this from happening again. 

Could a moderator please look into this, cancel this unwanted service, and issue a refund/credit of 12.99 € to my customer account?

Thank you in advance for your help.
edit o2_Solveig 26.09.2026, 22:14 Uhr pers. Daten und verschoben von o2 Mobilfunk → English Community : Mobile