Just have the GC tell him to rip it out and start over. But what kind of design details showed him what you wanted for edging? Surely your designer communicated with him about using a Schluter or a pencil edge? And then had diagrams or pictures illustrating that detail? Where did you find those tiles? They have a few issues as well.

That would be a "NO, not acceptable." Good luck with it.

Most certainly different workers! I'm going to guess the company got SOOOO busy (how busy Cancork?), they got SOOOO busy that they hired anyone with a trowel!

Your designer is your go-to gal/guy at this point. You bring them in, you explain what has happened and the designer then goes after the "setter" (I can't even use "tile setter" because that is a professional designation) with everything s/he has.

This is a very poor job with very expensive materials. Whomsoever is responsible, owes you a BRAND NEW shower install. And someone check the water proofing. If the GC allowed this, then I bet s/he didn't do anything to ensure water proofing was applied.

Get them to pull it down. And don't let anyone rest until it is done PROPERLY. You pay the bill ONCE. And you pay it once everything is done PROPERLY.

they do penthouses in the Mandarin Oriental Las Vegas etc

No they dont they may do happy hour though