O2 fraud

Hi every one, I am an English speaking student living in Germany and I have contract with O2. This July some one called from O2 and she spoke in German, since I don’t understand I told her to write me an email instead of calling and tell me what is going on. 

Then I received an email saying that I approved her offer to get a boost internet and a house number.

I was shocked, I went to the closest O2 shop and explained it to them, they told me I have to call and cancel, they helped me with it and that was over. 

Since I do not check my account often, today I saw that every month O2 is taking a lot of money from my account under the name of that contract. 

My original payment was 14 euros, now O2 is taking 26 and 42 euros every month. 

I really don’t know what to do.

I think I can cancel this contract, but I want my money back. I did not even receive a new contract by email or post.

What should I do to get my money back? I am really pissed off. 

Do I have to sue O2?

Thanks

Edit by o2_Manuela: moved to English o2 Community: Mobile. 20.11.22, 10:28 Uhr