Monthly statements always wrong

My monthly statements are always incorrect and to get help from the Seeff Sandton office is another mission. I’ve sent an email to Virginia which hasn’t been responded to and I don’t know how to proceed. It’s either you’re overcharged or undercharged and it becomes an issue in future with them correcting mistakes they did and it’s an inconvenience. Why is it that they can never and I mean never get the correct figure for your total amount to be paid? I feel like there are some funny activities happening with monthly figures, someone is deliberately putting wrong figures and keeping money for themselves. I was given Virginia as the contact person/manager should I have issues with my statements but she never replies emails and now I’m stuck not knowing exactly how much I must pay and why are the statements always missing figures or completely incorrect