SARS efiling - DO IT OR NOT?

A few of my colleagues and I did efiling for this and past years. A correspondence notification was sent requiring us to forward certain documents, which were duly sent and a reply correspondence sent back informing us that there were refunds due to us (DUE TO YOU) within 48 hours. After waiting for about a month without getting a refund, we made inquiries only to discover that we now owe them (DUE BY YOU).Each time one makes further inquires the higher the DUE BY YOU amount increases.