u/Few-Cod-6378

Hey all
I have a 2023 CX-5 that I bought as a CPO.
During the service yesterday at a Mazda dealership they told me that the tensioner is leaking fluid on the belt so both need to be replaced, they wanted $650 for it

The cars less than a year old and under 10k miles
I told them this should be covered under CPO so they agreed to replace the tensioner for free but now want 220 for the belt.
My question is that do I even need a new belt? Aren't they supposed to last a lot longer?
220 sounds like a rip off and since it was damaged because of the faulty tensioner shouldn't they cover it under warranty?