cancelled account

I cant believe it takes almost a year to correct an account that was cancelled, I have all the emails and every time I call I get promised someone will contact me and been weeks since some contacted me, last conversation was that they just need to speak to manager but been a month since then, every week I send emails because on the phone they say you cant speak to account department but they never call back, lawyers calling me for money after ADT statement shows we paid our last payment when we cancelled but ADT say we still owe them, they need to look at the own staff in Jeffreys bay and cape town that works with accounts of the customers, ref number is E***