No response and unable to close a paid off account

Last month I believed I had paid my LAST payment to my RCS Game account, however I have just received a statement where I have been charged: interest, a service fee and customer insurance(just under R60 in total) when I do not owe anything at all on my account. I do not even understand how this is possible as I had believed once I owed nothing that these fees would cease until such time as I purchased on my card again. I am currently overseas and unable to call the call centre to sort this out. I am receiving no response after multiple emails to ********** and other email addresses