Vodacom Messed up my Credit record by submitting a default while the payment was done in time

Vodacom sent an incorrect default to Experian. Meanwhile they have the statement showing that they debited at the same 2nd date they used for the past 5 years. I have just realised they the did it even last year again... I tried to fix it myself because they are not helpful. Below is experian's response even when i sent them the Vodacom statement showing that payment was debited... ***

*********** | 12:26 PM (6 minutes ago) | | to me

Good day

Thank you for contacting Experian.

Please provide us with a letter from the credit provider stating that you have never missed payment for the disputed months, unfortunately without the letter we will not be able to assist in removing the missed payment. An account will be reported as being in arears where the consumer makes the payment one day or more after the agreed payment date or when they are paying less than the original agreed instalment. The allocation of the payments is system generated and the system recognizes the payment after due date, regardless of how long after due date the payment was made, as being in arrears for the particular month.