Cancellation of contract

My O2 number: 030 - 35xxx

Hello, I live in a student dorm and from May 2019 onwards I have to pay compulsory internet through the dorm operators. Therefore I have already written to O2 by mail to cancel my contract starting from last year, including a letter from the dorm operator saying that I have to use their compulsory internet.

I have also already sent my O2 router back. I would have remained with my O2 contract but I have to use the dorm internet instead! Therefore I would like to stop being charged from O2.
It would also be unreasonable to pay the cancellation fee given it's not like I'm moving abroad, the O2 cancellation is out of my control.

'My o2' has not changed the date for the Vertragsfrist, therefore I would like to know when my contract will be cancelled.

Kind regards

Edit by o2_Marc