bad service billing

i am very disappointed with the service am getting with the billing department 1. i made an early payment to my account and the sent through a debit order 2. my account was handed over to collections on the 10/05/2018 mind you payment was made on the 22/04/2018 and my account was block on the 12/05/2018 visited one of you Telkom store in Clearwater no joy was received as i was referred to the contact center later that day my account was unblocked as i have sent proof of payment ,today i get a message telling my my account is handed over to Nudebt how did that happen? I am very unhappy with the poor service i have been getting