Unfair warranty claim denial for Renault Triber engine chain issue and parts taking more than 30 days to arrive in South Africa

I purchased a Renault Triber in August 2023, which recently developed engine chain issues. Despite having a valid warranty, my claim was denied due to alleged tampering with the plugs. However, the service person at Renault Cape Town indicated that internal engine issues should be covered as no signs of tempering was noted in the engine. I supposed to pay R30,000 for the repairs, with R15,000 upfront for ordering parts from overseas. It's been over 26days, and I still haven't received the parts. I'm seeking assistance from HelloPeter to resolve this Matter