Telkom Unwilling To Repair Device That is Under Warranty

I bought a lonovo idealpad device from telkom on 09 August 2018, the device comes with a 24 months warranty. After 3 weeks I noticed that the device keeps on hanging or freezing every few hours of use, each time when this happens I have to restart the device.

So I went back to telkom and asked them to fix the device for me, they advised me to call Platinum Warranty or send the device to Partserve as telkom does not do the repairs on the devices. After Partserve did the diagnosis on the device, they told me that they will charge me for re-loading the OS because the warranty apparently does not cover the OS damage.

If I buy a device and it breaks down whilst under warranty - I expect it to repaired at the sellers expense not unless the device has a physical damage.