Getting handed over for a closed account

In Sept 2014 ADT bought out SSG. We did not want to be covered by ADT so we cancelled the contract, paid the cancellation fee/outstanding balance. Yesterday I get a Letter of Demand (dated 5th Nov 2015) stating that I owe R2598 according to them the original debt is R46. How does R46 become R2598???<br> <br> I have the final account balance given to me by ADT in 2014, I have bank statements to prove I paid the amount to ADT with the reference number given to me by ADT on their own letter head signed by Padiso Ramothopa. <br> <br> I cannot understand how a matter from 2014 only comes up now in March 2016. I have had no contact from ADT and Debtsource (their collection agency) surely if someone owes you money you send a statement? an email? a phone call? or do you just get handed over for R46? This could have been sorted out so easily if someone had attempted to contact me<br> <br> Totally pathetic and just proves we were correct to cancel with ADT when they took over from SSG useless I tell you!