Bad customer service

I have paid my account on the 9th of March and after receiving several messages and phone calls that my account is in arrears, I have send them the proof of payment via email 5 times and still I receive a phone call today at 7 am in the morning demanding when I am going to pay my arrears amount. Shame on you Foschini for treating a loyal customer for more than 30 years like this. Please sort out my query. Because of you my credit rating is going to suffer due to your incompetence. What more must I do. I have given you proof that my account was paid.