Angry Customer

This company can make you stupid in front of magistrate in court. I paid this company on the 22 December, I got paid up letter in January. I have been calling and sending paid up letter coming from them to prove that the account is paid up. No respond on emails. On the phone they keep saying I should send paid up letter on email. How many times should I send same paid up letter coming from them? Their system is useless where by they can't see that paid up letter is been send to customer? They don't have qualified staff to deal with customer help? do we need to personally go to their offices to help them do their work?