Unsatisfied customer refund due to me

In 2014 I signed an agreement with African bank tracers to debit my account with an amount of R1560 (252002) & R380 (252001) which they have accepted. On the 15/02/2015 I rec an sms confirming that an add amount of R390 will be debited from my account I immediately contacted them and advised that I cannot afford the additional amount to be debited from my account. The consultant advised me that they were going to debit my account with an amount of R3116.05 (252002) and R681.52 (252001) I informed her that this is incorrect and she arranged it so that the correct debit order goes off my account. On the 19/03/2016 African bank once again debited my account with the higher amounts and the consultants I spoke to advised that I will not be refunded yet they can see the agreement made in 2014 on their system. African Bank please can you refund me my premium that you have over debited from my account as I did NOT default on any of my premiums since the arrangement has been in place.I have other debits that needs to be paid as well, total due to me is R2247.57 (incl the R390)... Please HONOR our arrangement