Pathetic service

Telkom is so pathetic and their service is poor. I called the customer care to change debit date and was advised to go in store for that,i went to the store and was told its changed. I got paod on the 26th and they debited on the 27th April not last day as agreed. Now i get an invoice with a penalty of R202.70 and am told it cannot be disputed as the date is the 25th on their side. What nonsense is that.