Settled Account

I had a woolworths account that I paid off in full in 2005 already and lately I have been receiving calls from a debt collecting company telling me that woolworths has handed me over as my account has a balance of R150. and now it owes R250, all these time they have never attempted to call me or write to me to tell me about the said balance. I was given the settlement amount by woolworths which I honoured whats worse it that the collecting agents are so rude and don't want to hear me out