Truworths Useless at Billing / Annoying Calls

I have tried to reason with them, tried to prove my account is NOT in arrears, begged them to STOP sending me nasty little SMS messages and nasty pre-recorded phone calls to no avail. I have one payment left and I will close my account because this must be one of the most annoying companies to deal with. I pay every month via automatic EFT before the due date and yet I still get these nasty messages and pre-recorded phone calls. In between these messages, I also get called and offered higher credit limits. So, according to Truworths I am a bad debt but they'd still like to offer me more credit? Just shows you how confused they are. I have noticed that when offering higher credit, the caller ID comes through but when sending you a nasty pre-recorded message, the Caller ID is blocked. I have begged them to stop contacting me - and I have proved my account is paid, yet they refuse to stop this nonsense!!!!!