Cancelling my contract due to moving abroad

Dear O2

I was an exchange student in Germany last year and I decided to get a contract with o2 because they told me that I could cancel it whenever I want if I really have to go back to my country. So far, I have been trying to talk with o2 staffs via facebook and email, and have been trying to cancel my contract since February. Before I left Germany, I had asked my german friend to call the o2 customer service talking about my cancellation. She told my friend that I could do it via email by sending a deregistration paper and a flight ticket together with about 83 euro charge because she said that I have 2 numbers (which i did not know it before). I asked my friend to transfer the money for me and he already did that. But I just got an email last week that I still have to pay for my number (again). 

My have all documents ready, which are

1) deregistration paper

2) Exmatrikulationbescheinigung

3) 2 letters of agreement (since I have 2 number) that o2 is allowed to charge 3 monthly basic fees.

But the problem I am having now is that I have neither a notification of your new, foreign domicile because I am living in my parents' house nor a confirmation of your new employer because I am not working. In my country(Thailand), we neither have to deregister from the country when we want to stay abroad nor re-register when we move back to our own house. What I have now is a "House registration", which has my name on it since 2017, but problem is that the House registration is in Thai language. Am I allowed to use the copy of my house registration in Thai instead of the notification of new domicile?

Ps. Do I have to send the documents by post only or is there any other possible way ?

Thank you in advance

Best regards,

Disorn Ratanotai