Something like fret wear can be subjective to personal preference as to what constitutes excessive wear. Some people are so obsessive about their guitars they have very little tolerance. And possibly the sales person that evaluated the guitar has way more tolerance as to what constitutes excessive wear. I'm not necessarily defending them but if thats the worst deal you've had in 12 years then you've been very lucky. Since you are in the US would it not have been easy for you to return the guitar to them to have them perform some fret work on it?