SIM card cancellation request not cancelled

Hi,

I expressed interest in a new mobile phone in branch on 14.07.2025. after discussion I signed up for a mobile phone and a SIM card. However shortly afterwards I changed my mind and was not interested anymore. Within a week after receiving the mobile phone and the SIM card I sent both back (telephone and SIM card) to the customer service address in Nuremberg along with a letter in which I clearly  said I was no longer interested in neither and that I wanted to be cancelled. I received a confirmation email saying my request had been taken into account. 

After noticing a direct debit in mid August I called customer service on 18/08 at 16.05. The agent confirmed that they received the phone, the letter and the SIM card back within 10 days of signing up. He also confirmed the cancellation of the SIM card (phone number ending with 8159), saying I would receive an email and a confirmation letter within a week. I still haven't received neither of those. I called again on 03/09 and was told I should have cancelled the contract in branch as I signed up in branch. But how was I supposed to know that? Nobody told me and my contract said the way to cancel was per post, which I did. In branch they said cancelling the SIM card was not possible without further explanation.

Yesterday I noticed another direct debit for a SIM card I requested a cancellation for and that is no longer with me since 2 months.

Before considering the next steps I thought I would share my situation here. I want the contract cancelled and a refund of the money unfairly collected .

Regards,

Edit o2_Kathi 10.09.25 Moved from the section o2 Mobilfunk to English o2 Community: Mobile