Get's invoiced for a closed account

My account was SETTLED IN FULL AND CLOSED over 2 years ago. The settlement amount and confirmation was given to me by a Diners Club representative and I even called after the payment to confirm. To this day , I am receiving invoices from Diners and insane claims that I still owe some money. A month ago I again contacted Diners (taking my calls to the company way over 10 in the last month, which is ludicrous as DINERS is the one that made the mistake , and they should be doing everything in there power to contact me) My account was sent to a team leader (who never picks up his phone *** or calls back when I leave a message or his colleagues send him an email. It's been a month now and I still haven't received any feedback. I have called 4 times the last two days and all the accounts department can tell me is that the team leader will contact me. Also there is a recording made in January 2016 where I was informed that Diners owe my to the amount of R4000 which I want to follow through and keep Diners responsible for as that made caused me to make financial decisions based on your information. I have all invoices filed and I am awaiting your phone call recordings.