Do DSTV know what they are doing with our accounts?

DSTV overcharged me by R154 in July 2019 and again by R108.62 in January 2020. However it is virtually impossible for me to get these matters resolved. This is because I have signed a debit order with them and DSTV themselves don't know how their own system works. It seems to me that the months transactions are only allocated to an account at the same time the debit order is processed, so nobody knows in advance what transactions are going processed to the account and how much is going to be debited to your bank account, until it actually happens. Therefore, instead of crediting your account with the amounts that they have confirmed are definitely overcharges, they "have" to wait to see what the system does on "debit order processing day" because the system may just know exactly what it is doing and may just process credits for these overcharges anyway and they don't want these credits to be raised twice. The problem is that the system again does not do what they expect it to do (in addition to not passing these credits) and a brand new problem is created. And then guess what? DSTV don't want to touch anything (.ie. both the old and new unresolved problems) as the system may just correct everything automatically in the next monthly cycle and so the problems just continues unaddressed from month to month and often mounting in complexity! But don't you dare cancel your debit order and simply make a direct payment of the correct amount due! Your DSTV statement will incorrectly reflect an overdue status and they will have no hesitation in immediately disconnecting your service, even though the problem lies squarely with them! I am losing all hope with DSTV!