unexplainable debits

Hi!

I just noticed that I was debited almost 8 euros from my credit. I have no idea why. I have a prepaid contract and the next renewal is on the 17th of august. Online, in the list of top-ups and withdrawals this amount doesn’t show up. 

Can someone help please? I have the Kombi O2 Prepaid S

Thank you! 

Edit by o2_Katja: Moved to our English Community