Breach of contract

I have had an agreement with Station finance that they will be running the debit orders on my salary date. I have requested for a loan on the 01 December 2018 and on the 07 December 2018 they have deducted R1090 +R195 = R1290 which was only due on the 31 December 2018 as per agreement. I have called them and they have advised me that they cannot reverse the debit order. all I want to know is what is the point of a client that read terms and conditions to sign an agreement with Station finance if they can still do as they please on my account. I want my money because the fear that I have is when ever I get money Station finance will just deduct. it is really ****ing me off because I need to go home but hey I have no money because of them. I WANT MY MONEY ASAP.