The fabricator made the mistake. If they cannot match the granite batch color then they should have to replace the whole countertop.

"Industry standard" is BS. They are going to fight this as it is the cost for 17' of new granite plus the fabrication. Could be small claims court. Or, if you have not paid them, don't. You may have to start over but hopefully you have withheld money to do so. After this mess, I would be reluctant to have them come back into any house to change even a light bulb.

it would be great if you could post a picture, but it sounds like a do-over

Yes, they need to give you a new counter. I would think the sink cutout is something a fabricator does all day every day. The fact that they made this error at all is alarming. More alarming is the BS about “industry standards”. Wow, are they trying to snow you. How did you find them?

they were recommended by a friend

You need a new top period. Industry Standards my ..........

Thank you