PICK N PAY CLOTHING ACCOUNT

I am disgusted with this company. I have a clothing account which is paid on time every month. On the month of November I received sms's to say that my account is overdue. I called 3 times to ensure my payment was received. It was "escalated" and resolved on their end. They have now dropped my credit score by 35 points for their lack of financial admin. Today I received a mail from their debt collectors. I have made several calls over the last month with multiple emails including my proof of payment. When will this get resolved? After I take them to the credit ombudsman?