nashua mobile- calling me about a bill that was se

Nashua mobile has handed my accounts that I have settled in 2009/2010 because I do not have prrof of payment ago, I mean they say I owe them and I know I have settled when I was under debt review.this is the message I am getting on daily basis:From: Alistar Brink<br> Re: NBA Nashua Mobile Account<br> <br> Client Account number: ***0<br> <br> Our Reference number: 2NSH022871<br> <br> Attention: MS SIKWAQE(mnguni) <br> <br> Subject: NBA Nashua Mobile Account <br> <br> Dear MS <br> <br> <br> Your NBA Nashua Mobile account has been handed over to Norman Bissett and Associates for collections. We have tried to contact you and have had no response.<br> <br> Our client has instructed us to collect the full outstanding arrears due on the account.<br> <br> Contact ***or reply and consultant will gladly assist in providing you with any information in regard to your outstanding account.<br> <br> If you have settled you account please provide proof to ***<br> <br> Once payment is made kindly fax proof to *** with your contact details and we will call you back.<br> <br> <br> Norman Bissett and Associates is governed by the Debt Collections Act (Act No 114 of 1998),<br> <br> Yours Sincerely<br> <br> Norman Bissett and Associates<br> <br>