ADT pursues me for work done for someone else

I am being pursued by ADT's debt collector Debt Source for a sum of R1 896.39. On investigation I found this is for installation work done in 2014 - strange as I haven't had an account with ADT since 2011.<br> <br> I eventually established that the work was done in Riverclub Johannesburg (I reside in Parkview) for an entirely different person. Even though I have a different customer number and address to this person I am being pursued for this debt.<br> <br> I was also never made aware or sent an invoice for this amount. The first I was made aware of the issue is when Debt Source sent me threatening letters demanding payment. <br> <br> How is it I was billed for something erroneously on an account which should have been closed 2 years earlier? Does anyone at ADT check customer numbers and addresses before issuing invoices? On what basis does ADT issue an invoice but never send it to a customer (falsely in my case), but then have a debt collector pursue them for the debt?<br> <br> I have never encountered such incompetence!!! Its also infuriating that I have to point this out to ADT and then wait for them to rectify the issue. I am still waiting for ADT to sort this out!!!