3 months since cancelled line and still billed!

I just received another invoice from after cancelling my ADSL and phone line after moving from my previous residence 3 months ago!<br> <br> Telkom's call centre is useless! Their staff are untrained! Their systems are pathetic!<br> <br> I refuse to be held liable for payment for their own incompetence!<br> <br> I already called in 4 times to address this including mailing their so called conflict resolution department!<br> <br> I expect this matter to be addressed immediately!