Unable to see if my o2 contract has been cancelled

Hi,

I have tried to cancel my o2 contract now on 3 OCCASIONS. I haven't received any more information if it has been cancelled now. I have sent a letter with 

Einschreiben Sendugsnummer : RR 8089 8110 2DE

This was confirmed to have been sent.

I am leaving Berlin on the 26th of July and I have closed my bank account. I have also sent 2 fax today to the number : 491805880088. One is referenced "121" and the other is "shailpatel". I have received confirmation emails that they have been sent. I have also called by telephone and they said they will cancel my contract and send me a letter. I never received the letter.

Please reply immediately as I have seen many people on this forum have still been charged by your company despite believing that they had cancelled their contract after moving abroad.

I have a ALL IN S FLEX contract.@o2_Bernd@o2Admin

Does anyone know what I should do??

Kind Regards

Shail