Clutch kit worn out

I test drove the car I bought, it had a problem with a clutch that was too stiff and the sales person told me it's because they put a new cable and it will be softer as time goes on but they'll try to loosen it at their workshop.After few days I made a follow up telephonically only to find that nothing was done. I said to them am not gonna take it if is not fixed and they promised they'll attend to it. It happened that the car was delivered to my place as I was driving my old car. On driving it the next day I could feel the clutch is a bit loose but still not perfect and I took it myself to a workshop and was told it needs a clutch kit of which they replaced and it was costing R4174. I contacted Gys Pietzer Wonderboom branch and told them I fixed the car myself, their response was that they can only pay half of the amount. My concern is, why not the full amount. I suspect they knew the car needed a new clutch kit