Shame on you Dstv

I am frustrated, disappointed and very angry with multichoice. In July we upgraded to the explora ultra that was supposedly going to cost us R649. 00 on a price lock for 24 months. Ever since we installed this, it has been mayhem after the other amd Multichoice is failing us. The installation was scheduled for the 3rd August which was a Tuesday if I am not mistaken. However it was done earlier on a Saturday, no problem there. We were then informed that we had to pay R440 pro prata which we did. We then received a message informing us that we must pay R539 on or before the 28 August which we paid. On the 31 August Multichoice debited R788 bringing the total payment to R1327. Today on the 10 September as I write to you Multichoice has disconnected our services claiming that we owe R876. 36. Can Multichoice please explain how that amount was reached since they still owe us R539.