Telkom Over Charged me and is threatened to take me to court even when I'm no longer working and unemployed

I had a contract with Telkom for a router and when they delivered two routers instead of one, I immediately reported the error and the second router was collected within a week.. now come month end the deducted double the amount they were supposed to deduct.. so I was still paying for the second router even though I had it collected. I again informed Telkom that I'm being double charged and they should rectify the mistake . But it went on for almost a year despite my numerous attempts to have the second contract cancelled. I later stopped paying and two years later the company resurfaces and claims that I owe R3k+ which I refuse to have paid cause I was double charged from day one which was never attended. Now they threatening to take me to court. I don't even have any source of income at the moment. Never signing up with Telkom ever again.