DStv *****ing my money...live

End of November I took the DStv price lock and ever since then I've been having endless problems. I had to pay the pro rata which was fine. My debit order is for R598 but every month they are over deducting and deducting before the debit order date. As a result the debit came back one month and I had to pay in R800 on the 5th March. They said I didn't use a reference so I should email the proof of payment and the would credit me. This was done on the 6th March but I still haven't received anything. End of March, my account was debited for R1600. I called in again and I was told it's been escalated again. I have in the last week, called in 3 times and still no joy. It seems like I'm paying for premium and compact packages now. They have never debited my account with the correct amount of R598. I can't keep calling in and having my money take for nothing and no one can sought out this issue. I am tired