termination of contract

Hello.

I'm Changwook Yoo.

I sent a termination form of DSL to O2 by fax 3 weeks ago.

However, I haven't received any reply from O2 about my termination of contract.

In this case, what do I have to do?

I tried live chat, but it doesn't work because nobody answered, even though I waited for more than 20min.

Also, I tried to call o2, but I cannot speak German language, so I cannot understand the directions.

Therefore, I wanna deal with this problem via this community or e-mail.

Thanks.