I noticed a debit order on my internet banking Pro

I noticed a debit order of R99.99 reference was Mzansitel who I know nothing of. I do not check my bank statement so I wasn't aware money was being ****** from me because the amount was less than R100 so I didn't get notifications when the debit went through. I tracked this company down and spoke to some lady called Tracy who said she will look into it and refund me if it was a mistake. I have never heard of these people before and how in the world did they get hold of my banking details? They finally refunded me R500 because I didn't even check how long they have been taking money from me. I checked my statement again and to my surprise there are two more debits for R99.99 each one from Mediplus and the other one just says DRE and then my identity number. I'm very disappointed with FNB and I now strongly believe their personnel is involved in these ****s. How do these people get hold of our details, a few years back my debit card was cancelled on 3 occassions and everytime they told me I cancelled them and I was charged for a replacement card. What puzzles me about this is that back then you would call their lost card division and who had the answers to the questions they asked in