Contempo Incompetence

I have canceled my account numerous times at Contempo clothing. I have spoken to many assistants over the help line that said they could assist but I haven't prevailed at all. I physically went into Contempo to be assisted and haven't succeeded either. My account payment is up to date, I am actually in a credit of approximately R500 and they keep on hammering that I still owe them money. To be quite frank I am fed up.