Cancellation of Expired Contract

My 24 month LTE expired in August 2017.

I've filled out the cancellation form, and sent a number of emails to, both, the ********** and the ********** email addresses, as listed on your website. I have not even received as much as an acknowledgement of receipt!

I've tried to make contact with your support personnel on Twitter, Facebook, email, as well as your online contact form. 90% of the time, I get no response, and when I eventually do, I am told to send the completed cancellation form to the above-mentioned addresses.

It is now November, and I am still being billed for a service I can't use (I've been out of the country for 5 months).

This is **************** and I refuse to pay another cent. If this matter is not resolved immediately I will have to take it to the ombudsman.