Threaten client for their job not done!!!!!

Every month I pay RCS the same way with a loaded bank beneficiary, meaning all details stays the same except amount needs to be entered every time. Been doing this since I had the account last year. All the sudden on 11th July 2018 I received SMS stating I need to pay my installment. Phone the 12th and at the same time sent the proof that payment were made on the 2nd of July already. Late Sunday 15th July received another sms stating my account is in arrears by R3000+ all the sudden. Phoned Monday 16th again, in which they will escalate. Tuesday received a mail from their team leader stating again that the account is in arrears. Wednesday morning received a mail from their manager with exactly the same response and indirectly threaten me by reporting my credit status. Immediately contact him but all the sudden he is in a meeting. The consultant advise that they will only allocate the payment from the 2nd of July within the next 24 hours due to a process they have to follow and the balance still owing is only due the 1st of August. If there is a process in allocating monies paid, then don't hound and threaten your client until you have done your job and don't state money is outstanding if it is only due at month end. And sure as well don't threaten your clients with their credit status if you can't action your job immediately or do it right the first time!!! Your service and procedure are shocking!!!!!