Telkom Debited me the day before i got paid, Admits it isnt my fault but is charging me R200 anyway!

So last month Telkom decided to debit my account on the 24th because the 25th was a Saturday, their explanation was they were under the "Impression" that since the 25th was a Saturday I would get paid on the 24th. I didn't have enough funds in the account to cover the Debit order so it bounced. I was charged a penalty by my bank, I called in and the Agent told me that I should just make a manual payment and it will be fine, I specifically asked if i wont be charged for the rejection and he said no on a recorded call (27th August 2018). I made a manual payment immediately, Today i get an invoice and I have been charged R200 for the failed debit order. My salary comes through on the Saturday if the 25th falls on it, i have been with Telkom for 5 years and have been paid on a Saturday many times before and you have always debited on the Monday so why do you now decide to have the 'Impression' that I got paid on the Friday? I just spoke to a team leader who first **** to me and called himself a 'Manager' He said he agrees that the problem is not my fault, so how can you justify charging me for something that you admit is not my fault.