Their accounts department is a mess!!!!!!!!!!!!!!!Debit twice credit once really??????????

Just a quick question????? has DSTV got nothing to do??? I have checked their statements today just for interest sake because this month I paid R890.00 now next month is R1001,00??????? Where is the difference??????????? It is a debit and then a credit? What de hell and if you dont pay that amount that is owed on your statement they just cut it off?? And to make an inquiry it is a nightmare???????????