Contract overcharge/no night data vicious cycle

I have had this problem since I upgraded my contract at the beginning of 2015.<br> My previous contract was Internet Promo 5 10Gb (R199) with 10Gb (R100) of Nightsurfer data. <br> When my contract was upgraded to LTE 10Gb+10Gb (R439) the 10Gb (R100) Nightsurfer charge still remained on my bill.<br> <br> I have been paying R539 per month for 10Gb daytime data and 10Gb nightsurfer data. When I tried to correct the issue by logging numerous cases the 10Gb of nigthsurfer data for which I pay R439 is removed. I am then left paying R439 per month for 10Gb of daytime data.<br> <br> When I noticed my nightsurfer data was removed from my data bundles I logged a case to get that corrected and it was corrected partially and the next month I was charged pro rata for that partial nightsurfer data.<br> <br> I tried to get things sorted out again recently, making sure they understood that I do not want my 10Gb nightsurfer data that I am paying for with R439 to be removed but it was removed.<br> <br> I have even gone as far as making a month to month analysis of how much I need to be refunded and how much of nightsurfer data I did not receive but the problem has just gone around in circles. Please help me with my vicious cycle