Matt and May fix my account

Good day I checked my Dec 2017 statement it indicated that i still owe them R75 .I paid the balance t of R663.85 which was on the 19th of Dec.On that statement there were 4 charges added before the 19th 1. collection fee 2.sms 3.email 4.phone call fee.Do they have to tell me 4 times and besides why do they have to charge me to notify me balance i owe ?Its like the City Council charging me for sending my water bill what is that? I did not refuse to pay. on the 26 Jan i received an email from Rhyno Petersen which stated ""Kindly be advised that we have made a once off concession reversal of R75.75 for the collection fees charged on your Mat & May account."" But to my surprise the statement says i owe now R46.83 where is that amount coming from ? My account should be R0.00. I sent a query to customer services on the 20th Feb still no reply. Please honour your word Rhyno and fix this.