How do you end a contract with this useless company

HI to whoever sees this, after multiple attempts to call, use online support and even use facebook to try to close my account, i am no further. I took out a contract 2 years ago, which i was told in store was only a 12 month but that is another topic, i am now reaching the end point and want to pay to cancel my contract as i have never even used the sim card as all i wanted was the phone to replace a damaged one. 

So i thought it would be fairly simple to end, simply call a support number, talk to a person pay the difference and done. How wrong could i have been, you call the number just to have a 3 minuet automated message with menus just tell you to go online. So you go online and guess what i dont have an account, so i go to create the account, but wait it wants to send my number a security code (the number i have never used). So i go to live chat, just to be told no one is available try again later. So i tried again later just to get the same message. I then went to facebook as i thought there could be a chance to get to a person, only to find multiple post from people saying the same thing, after complaining to a post reply the best answer i got was post on her which came from the ID reply. 

So all of this for some cheap £15 a month contract which currently looks like i have no way of cancelling, i could of course cancel my direct debit but then i am in the wrong for doing that. So if anyone exists at this waste of space company, please contact me to end my contract. Dixon group should be ashamed if this is the level of service they want to give, and then to have the bad taste to say we are doing this to prioritise vulnerable customers during this period, how are you doing that if they cannot reach you by phone??????????????