Following the expiry of the manufacturer’s warranty on 2009 Volvo V70 2.0D R Design I bought an extended 3 year warranty from an independent company. I have had a warranty previously with my Saab 9-5 and had a few claims with no problem.

Recently my alternator failed at 70,000 miles. I made a claim and was told that they reserved the right to request a contribution towards the parts and or labour in the event of a valid claim being admitted if the vehicle enjoys a better condition after repair than it did immediately prior to failure. They offered me 50% of the total claim, minus my £50 excess. Given there is no repair kit available (I was told by the dealer they dont fail at this age) I had to have a replacement shipped from Germany, the total cost being £590.
I wrote to the warranty company confirming that this clause isn’t in my policy documents and that they hadn’t written to me to confirm this change and that given this statement and I am unsure as to what is actually covered under the warranty. I also confirmed that the dealer had said that no repair kit was available and the failure was exceptional.

The warranty firm has refused my appeal and have directed me to contact the insurance ombudsman.

My question is - Am I being unreasonable and should I accept this 50% payment as I have had 50% use of the lifespan of the alternator - or should I challenge the decision with the view that the alternator worked before and after replacement?