Cancelled my tv licence

I helped a friend to purchase a tv the stockest was easy to take my detail, of which this friend is no longer in the picture and I'm still battling to cancel the said tv licence ... I have never owned nor will I ever own a tv and am still prompted electronically to pay for a service I do not own. This occurred last year and we are nearing the end of another year, I've just had enough of poor customer service quick in service when to favour them.