Incorrect Debit Order Date and Service Experience

I am writing to raise a concern regarding my WesBank loan debit order. My signed debit order arrangement is for the 25th of each month; however, this month the debit was processed on Friday, before I had received my salary, which is paid on the 25th. As a result, I was charged R150 for insufficient funds. On Tuesday I phoned and queried I was promised to have feedback the same day ! He even phoned me to ask for my statement before he refers to another department. He said he will send me the email address to send it to him! I am still waiting for that info!!! I phoned x3 times again the same day and couldn't find the correct person. Nobody has given me feedback. This is bad service!!! I kindly request that this matter be urgently investigated, that the reason for the early debit be clarified, and that the R150 fee be reversed.