Jaguar SA - no integrity!!!

I drive a E-Pace, and reported an issue with the car rolling back, while the car was still under factory warranty. It took Jaguar (Centurion/ The Glen/ Menlyn) more than a year to identify the problem. The car is out of factory warranty now, and the extended warranty is refusing to pay (because the issue started while the car was still under factory warranty). The level 4 technical person determined that there is an issue with the gearbox oil - which needs to be flushed. And now the best part - Jaguar is prepared to pay for the oil flush as part of "good will", but I need to pay 60% !!!!! So, I need to pay 60%, because it took Jaguar more than a year to determine what the issue is!! They can forget about it. The issue was reported while still under factory warranty. Jaguar SA, is just sitting on the sideline, hoping that we will go away. Which is NOT going to happen, I've struggled for a year to get Jaguar mechanics to find the issue, I'm not going to give up now.

Jaguar SA- please have some integrity and dignity and do the right thing here.