Bad service

I'm having the worst experience with cartrack,I even regret doing business with them .yes I admit that I did miss a couple of premiums however I received an sms informing that I have pay R800 and something of which I paid.but not so long I'm getting an email stating 543 and now they have handed me over to some attorneys and off which I did query matter showing proof of my payment and sms received of the outstanding amount.This is bad and clearly they do not take their customers interest at heart instead it is more of them collecting money and harassing people.how do you even hand over a person for just 543 yet I have proof that I have paid .bad service altogether and quite disappointing.