O2 is not Responsive ? for Terminate contract

Hello,

I had signed contract for 2 years - DSL internet. Ending on april 2017.

I wanted to terminate in September 2016, and I sent Written letter, signed and Faxed to them, Sent via Email.

But I havent received any response from them úntil now since last 15 days.

Very pathetic customer service i feel.

Very poor customer service.

Please let me know if there any other means to Terminate Contract ?

thanks

sampath