Horrible After Sales Support

I have been strugling to cancel a contract since April, eventually in May (7th) when I called in I was given an email address for the so called "Regional Manager" Simon. To date Simon has not answered my email sent. I now called in again at the end of June (20th). Again I spoke to a "Regional Manager" called George who refused to give me his email address. Now apparently I need to sign a form. Which no one has mentioned in any prior conversations.

To my understanding I signed a 36 month contract starting on the 26th May 2016, I was made to understand that my contract will end and I could cancel 3 years thereafter. So as per my understanding that would be on the 26 April 2019. So I am now going on to month 38 and qcxording to them I have another debit order that has to go off before I can cancel.