IQ Academy please pay my money back

I registered with institution sometime last year and later deregistered from the college. I was told that there is money that i must pay since i received books of which I agreed. My problem is I later notice that there is another amount of money coming out of my account paying the same college. I then call the college to enquire what was the money for and was told that I missed a payment so that's interest for that, of which I have never missed any payments with them till today. I feel that IQ Academy is busy robbing me and I need that money back. Cost of living too high.