Multichoice incorrect billing / communications

I called Multichoice on the 4th of Aug 2015, where they informed that I need to pay R486.32 in order to get my account up to date. (I usually paid an annual fee, but changed it to monthly payments this year due to my husband not being employed). when i call today, i was initially told that i need to pay the subscription and xtra view for Sept 2015 which is R779. and was then told that i owe R150, and that i was misinformed in Aug 2015, and seconds after i was then told that i now owe R292, not R150. this is totally unacceptable. according to me, i should only pay R779. I need someone to respond to this. I would assume that Multichoice has rather advanced recons and billing systems to ensure that we get the correct results and feedback. i will the R779 for now but need someone to explain what the issues are within Multichoice