TRACKING YOUR MONEY BUT NOT YOUR CONTRACT OR CAR

I took a three year contract with Tracker. My car was written off two years ago in an accident. The contract itself ended last year. Now they've handed me over to a collection agency even though they've confirmed I have paid IN EXCESS of what was due. The Call Centre and email service is pointless. Tracker has no business ethics. Either refund my money, withdraw the collection agency and apologise, or I will seek a civil matter against you.