fails advertisng and unfair practise

around this year 2017 my account was debited by loan tracker SA, which i have never agree or do business with them,i have asked them to cancel all those things and they told me that i need to pay for they service, i mean what service agreement did i enter with them mxm?right now they are threatening me with letters saying i will be blacklisted if i don't pay them ,who are this guys,please take me to court if you guys have to but i wont pay for something i did not sign for mxmLOAN TRACKER SA IS BUNCH OF ********,people be aware of this ******.