Ho to close an Edgars account - impossible

I am trying to close my Edgars account. I received a statement in October which showed a credit but still asked me to pay an amount for unspecified debits. I went to customer service in Brooklyn and they did not have access to my November statement. I went to customer service in the Mall of Africa and they told me that I must email Edgars. Meanwhile a made a payment which was more than I owed in the hope that it would allow me to CLOSE MY ACCOUNT. I returned home and spent 3 days hanging on the phone trying to get an email address in the end I emailed them all! No reply. I phoned again and finally found a, what I thought was helpful, accounts manager. She would not give me a reference number for the call but told me that she would email me my last three statements with a reference number. This was 4 weeks ago and nothing. 10 weeks now all in all and NOTHING has happened except I have an sms asking me yet again to pay an amount. HOW CAN I CLOSE THIS ACCOUNT? I HAVE GIVEN MY ID AND MY ACCOUNT NUMBER TO SO MANY PEOPLE WITH SO MANY PROMISES AND YET MY ACCOUNT IS STILL RUNNING.