Troubleshooting natural stone bench

Hello everyone,

we are currently having a new fireplace installed. Unfortunately, there was a mistake when measuring the natural stone bench, pictures attached.

The bench consists of 2 parts, unfortunately the beveled edge on one stone was measured incorrectly and it now extends a few centimeters too far in. Depending on the light, it is barely noticeable or it looks as if someone had used an angle grinder there. It bothers me, but it is probably not a reason to insist on a new bench...

Can someone tell me how to best fix this so that it looks as good as possible?

Currently, I have the following offers:

1. Price reduction and leave it as is (not really an option for me)
2. Remove the bench. The beveled edge should then be continued and sealed with dark silicone.

I’m afraid it might look even worse afterwards...

Does anyone have expertise and maybe an idea?

Thanks in advance!

Best regards!

Question 1) Who is responsible for the fault?
Question 2) Does it no longer bother you if you get a 50 Euro discount? Or 500? Or 5000?
Question 3) Is it a functional defect?
Question 4) What value does a visual defect have?

Answer 1-4) Either someone other than you is to blame and you cannot live with it, then you should have it exchanged, or you are out of luck.