I would recommend reading the bill. It tells you how much was charged for what. Maybe you forgot to send back your o2 rental router?

If it is a premature termination due to moving abroad:

How to do a cancellation of my DSL contract due to moving abroad?

Hi,

actually it looks like a normal bill, like the ones I received when I had the DSL service. There is no info.

I did cancel due to moving abroad and all was settled. But now that you say it, it does seem logical to be for the router, but I wasn’t notified of any deadline to send the router. I still intend to do it, but I don’t live in Germany ad I was gonna do it in a few weeks.

Thank you for your reply!

Kristi

The invoice is a PDF document with several pages. Please read all pages of the invoice.
According to the contract, the o2 loan router must be returned at the end of the contract, as the device is only given to you for use during the contract period. If you terminate the contract prematurely, you must return the device after the last day of use of your connection respectively immediately after moving out. 

Now that the calculation has already been made, you should return the property of o2 immediately, otherwise no refund will be possible.

Wow, thank you for this message! I will try to do it as soon as possible then!

Surprisingly I only got an online-Rechnung that is not in PDF. And I cannot access MeinO2 to read if there is anything, because it was terminated two months ago. So I cannot see the bill even if I want to.

Anyway, your comments were truly helpful, thanks again!

Kristi