Payment Overdue Notificaton

Good day<br> <br> My Account with Altech was closed & confirmed close. Last Invoice Statment received showed outstanding Balance of R650.64 was paid on 23.09.2015. <br> <br> Invoice ***<br> Account 1.***6<br> <br> On 12.11.2015, i received a email from Altech advising me that of PAYMENT OVERDUE even though my account have been<br> 1. Paid up<br> 2. Confirmed closed<br> 3. Cell no longer active<br> <br> <br> Pls can this nonsense be sorted out & i expect, via email confirmation that its a error & Altech to confirm account paid, up & account closed<br> <br> Thanks<br> George