Account showing arrears on an amount paid

<p>I have been emailing and phoning ADT since March 2016 with regard to my statement.</p> <p>My statement shows an amount outstanding for January, this was paid and in every email I have attached the proof of payment. It has been a year now and my account statement still shows this amount as outstanding.</p> <p>I am at my end with ADT accounts department. This is not the first issue I have had. How do I get this resolved?</p> <p> </p>