Premiums refund

I am disappointed in them, after selling my car, I forgot to cancel Insurence and the debit was running since 2015, until 2019 November, I called them I made them aware, ask me for proof that the car is no longer on my name I sent them offer to purchase from VW wonderboom where I traded in the car but they need something from Enatis which I can't get as the car is no longer in my names, all traffic people could do was to screen shot the info of which I ve sent to them but till today no answer from them