RCS refuses to give me my outstanding balance!

RCS is refusing to give me my outstanding balace, as well as a bank account into which to pay it. I've mailed them at ********** ********** as well as ********** and they simply refuse to give me my outstanding balance. On Monday the 3rd of September 2018 I received a statement for May 2018! Thus I have no idea what is the balance of my account. I'm in Zambia, so I can't call their customer line, and even when I was RSA a few weeks back I can't get through to an operator due the incredibly long waiting queues. I also can't create an online RCS account because the system refuses to accept my card number. I need to pay my outstanding balance and get my account closed. But clearly the longer my account stays open the more money this *********** ******** organization makes!