extar charges on my bank statement.

Do you still have a smartphone with o2?

I have one smart phone and 3 plans. The smart phone is charged around the 17th every month and the plans are all charged together around the 21st every month. 

Compare the customer numbers in the debits. Is there one among them that you don't recognize?

None of the numbers on my bank statement correspond to my customer number. Just what I assume is an account number which is similar across all charges sort of like an IBAN GDE9700000000142462, then possibly a tracking number or confirmation number which is different on all charges. 20294528, 22837398 and 2884067 (these change with every charge) And a long number T0010001B0000061 which is on my cellular device charge and also on the mystery charge. The monthy plan charge has a T0010002B0000060. 

Contact o2 via the contact form and ask what that is.

https://www.o2online.de/service/kontaktformular/

Hello ​@Alex LoMar ,
welcome to our o2 Community 😀
I can see the direct debit for your four mobile phone contracts. 
Then there’s one for the Samsung Galaxy S26 Ultra and one for the Samsung Fold 8. 
Does that answer your question? 
Kind reagrds, 
Solveig