Unfair and Cheating their Clients

My payment for January was paid at 09:00 Monday the 2nd February 2015 as the 1st was on a Sunday. on the 4th February 2015 my services where disconnected and reconnected the same time, but then I got an sms saying I now owe them R50. I called in to find out why and I was told that because my payment only reflected on the 4th February 2015 and I asked why you still disconnected on the same day, the lady said she will fix the issue and remove the R50 from my account. On the 27 February 2015, I paid my normal R295, but then again I got an sms saying I owe R57, I called in and was told by Palesa Makamu and a supervisor called Sinenhlanhla that it is because I did not pay the R50 that I owed in January. I told her to investigate as I did not owe them any money. She did and told me its not their problem, if payments reflect later on their accounts and I should have asked my bank to make the payment on Sunday the 1st. This is unfair and a way of multichoice to cheat customers of their R50 as they know very well banks don't run debits or stop orders on Sundays.