Billing 935 for compact plus for August what the hell.

On the 24th of August I paid an amount of R650 for my compact plus subscription and yet my account was short with an amount of R285. Which I don't understand because the amount for a compact plus is r520. Yes I activated the compact plus in July but his doea not mean I should b charged a whole R935 for August this is a price for a premuim subscription. Something is wrong on the billing and I want a detailed breakdown because the same thing happened in May as well. We cannot b ripped ofd by multichoice in these hard timea cause we really don't have a choice for a better supplier. I want this checked and feedback given cause calling the call center is a waist of time and money cause they don't even know how their billing system works. U can hold on for over thirty min while someone goes to check with a supervisor and still does not know what they r say or doing. What kaak service for the money we pay really.