Some 'clean' options:

Instead of full backsplash, a 6-8" high splash of same stone, paint above.

Full painted splash

Back painted glass

Large format tile

...

Thank you. I forgot about painted glass. I did consider windows but they would be off centered since the range is so decided that might not look great.
I will check into it.
I still think I prefer a full backsplash look but will explore the shorter version.

Look into the large format tile like suggested. It will give you a slab look ( which - depending on the layout- has seams in it ) . Just install with the smallest grout line possible. We just did one in our showroom and it looks great. Much less expensive and not as thick as stone.

So sorry you are having a bad experience.

Really how can we even begin to answer with no pics of what you are dealing with Post pics here in a comment DONOT start another post

I recommend asking them to supply a new slab on their dime seeing they messed up causing the shortage. They should be compensating for their mistake.

Yes, but we can’t locate more. A home builder bought a large quantity of the same material, so only have one left

Time to pivot. What does this actually look like? And what are all the mistakes that can’t be fixed?

Yonder, pieces do not match those next to them. We have an angled wall and the counter was cut incorrectly leaving a 1/2" gap at one end, see the photo with arrow where gap is. Handles are not alogned due to the incorrect angle, left sode is recessed, right is not. This can't be covered with backspkash as an appliance garage was planned for that location, do that 6' piece needs to be recut. peninsula top is crooked so some edge pulls are recessed and others are not. they plan to try to straighten in hopes the waterfall will align and handles will but that may leave sink less than straight. They may not have enough material for a backsplash that lines up with any pattern, so they are talking about cutting new in the opposite direction. We had two sets a bookmatched slabs for this job, so i can’t understand how it could be such a mess.

Oh gosh so sorry - what a pain! i would be tempted to get another fabricator (with a great reputation) in there for a second opinion - would be great if you could skip the waterfall and use that material for the BS

The waterfall is 57” wide Backsplash is 138” . we should have been able to get a bookmatched design here.

Ah I was thinking you had a waterfall on an island so two pieces - didn’t look at the photo close enough

The 11th hundred post on this forum about waterfall counters veins not flowing perfectly. "we should have been able to get a bookmatched design here." Please expand on that - does your contract say the pieces of the waterfall will be bookmatched to the counter? Did you go to the template layout to see how the slab pieces will flow? Regardless, given the vast numbers of people complaining on this issue, I think it is near impossible to get a perfect vein flow unless you have the most top-notch fabricator, you sign off on a layout that shows that, and your contract states that is what you are going to be getting. And the question is - is the absolutely perfect vein flow really important, or is it something we've seen on Pinterest (often photo-shopped) that we think is both attainable and a must-have?

4 slabs were not enough for all of that matching needed. The material does not apear to be natural stone, with the pattern all the way through, since first pic of the waterfall shows an unprinted white interior of the slab. It appears to be a porcelain slab. And there are a ton of those around to source.

These are White Lux Quartzite

You might be seeing the glue since I made them stop when I saw they did not March correctly

These guys are clueless hacks.

Of course the vein match is important. Especially in this situation because it is the first thing you see when you walk in. No fabricator, including this one, thinks this is correct and neither does the slab distributor. I expect the fabricator to make the best use of the materials. While something like this could be corrected, they made so many bad cuts that we don’t have enough left to do it over.