Unauthorised change in debit date,

I took out a personal loan with FNB over the phone. My debit order date was the 25th of every month (my salary date ) that we agreed on and I committed to. FNB changed this date without my permission to the 23'rd and as a result I have a unpaid debit order every month, resulting in charges on my bank account, and interest, then 2 days later they debit me the amount again. As a result they charge me interest every month. After paying this loan for 3 months at R1,936.66 a month I basically still owe the same amount as they charge me interest for the amount, then debit it again. <br> <br> I emailed the loans department and this is the response I received from FNB : <br> <br> Kindly note that we debit on your salary date. According to your salary dates, your salary was paid on the 24th March and the 23rd April 2015. Please provide us with a letter from HR stating you pay date so as to change the date. <br> <br> What a joke of a reply after I advised my salary date? Please adjust my account, go listen to the call and hear that I advised you guys my salary date is the 25'th. This left a bad taste in my mouth and after all the time banking with you maybe its time to move. My salary date is the 25'th. <br>