Wrong installments requested

Dont want to rate them. Since may not getting feedback on admin people to call me and if i call hold so long with no luck or get transferred around with no luck. They cant do allocations and installment calculations correctly. If you have a balance of R2000 they will charge an installment of R1800 in a 6month account option and then penalise the customers record as well. Need i say more thinking having a store account for credit record build up can go so wrong after being a customer for more than 10years already.