Charged for collection fees when payment was made but Edgars cannot allocate properly

What an absolute nightmare dealing with the new credit department of Edgars!! I completely understand that there were issues before with people not paying and that's why they had problems, but to treat someone who has never missed a payment like this is atrocious. I paid more than what I needed to pay in the same way as always but due to Edgars new systems they couldn't pick it up. It seems to eventually be sorted out after I sent proof of payment close on 10 times. I'm not 100% sure if they did allocate it as the statement doesn't show that far back but at least I am not in arrears. However I am being charged in excess of R75 for collection fees!! Excuse me?? Why must I pay R75 when Edgars cannot allocate a payment? As soon as I can pay the balance on my account I am closing it and will hopefully never have to support them again. I honestly cannot see the new owners of Edgars having much success if this is how business gets done.