over charged

I was called last year telling me that Capfin handed over my account and the lady told me that they are going to debit R500 monthly and the amount was 4577. And i do understand there will be fixed legal cost so far they have debited for 8 months which is R4000. but their statement says i have paid 3109. i was not told about this Receipting amount worth of 57.00. there is not fixed interest fee from this company they just over charge to gain that means the amount i was told it will be debit from account is no longer 500 but 443- the least that the company could have said was we need 557 i have sent emails to them and they fail to respond

12/15/2017 A: DEBITORDER PAYMENT POSTED, 5446-174 (500.00) 12/19/2017 B: RECEIPTING COST, RECEIPTING COST 57.00 1/15/2018 A: DEBITORDER PAYMENT POSTED, 5631-63 (500.00) 1/16/2018 B: RECEIPTING COST, RECEIPTING COST 57.00 Sub Total for : Payments received (3,101.00) Version Number: 1.0.0.2 It is in your own best interest to settle this account as soon as possible to prevent additional cost and legal action being instituted against you. Reference Number: ********** ********** Branch Number: 051 ********** 17219 MCS 2,709.72 219.02 2,490.70