No refund for annual fee deducted post cancelation

I cancelled my subscription with ADT at the end of November 2015, which they only responded to mid December 2015 after deducting the annual service fee for 2016. I notified them about this for them to refund the admin fee. They promised it will take a maximum of 7 working days to refund, however it is almost the end of January 2016. I have spent more than an hour on the phone just to get an answer on the refund but the next person knows less than the previous. I was then told I am not allowed to speak to their managers etc. but when I finally did they said it will be released on Tuesday (19 January 2016), but when I phoned today (21 January 2016) there is no record of this. I even proposed to come and collect it in person if it is to difficult to process a simple refund.