Shaddy debt collectors

I tried to prescribe my 4 year old dormant debt against ADRS debt collections however firstly the consultant I spoke to didn't know what debt prescription is. I asked him to escalate the matter to his superior who made a false statement saying I made an arrangement on the debt in January which I disputed then she changed her tune saying I changed my fone number during the course the debt which was another blatant lie, I told I would report her to NCR and she unashamedly told me to go ahead