Unfair claim rejection

I have submitted a warranty claim for my Mercedes Benz 250d. After several follow ups the claim is rejected on basis that there was a late annual service in 2023. According to them they calculated the km inbetween the services done in 2022 and 2023 based on the 15000km intervals.

I have just checked with Mercedes Benz Rustenburg and they confirmed that my service intervals is 20000 ks and also my service plan provider MOTORITE gave the same confirmation.

What frustrates most is that it's been two weeks of long waiting on que follow up calls and the rejection based on assumptions without checking facts.

We take insurances so we can have some peace of mind when these things happen but it's sad that the insurance company is the one that will frustrate you most