tv on account broken still under warranty cant fix

We bought a High sense TV from game Middelburg 27 months ago, the TV is now broken and still under warranty, but because i do not have the slip they can not fix my TV? this TV was bought on account but apparently they do not have any paperwork on their side that shows i bought the TV from them. the TV is not paid up yet but they don't have any paperwork??? i pay my account every month. i would like to have my TV fixed. it has been 2 weeks already (arguing back and forth, who will be fixing the TV) The manager tried to help by saying that he will pay half and i should pay half but i do not feel that this is fair as this TV is still under warranty and not even paid up yet.