Is the wall flat? If an uneven wall surface is causing the lippage, replacing the tile won't correct the problem.

To me, it looks like it would need to be removed and re-done to really get it correct. Sometimes lighter grout (white) would hide imperfections more than a darker/ contrasting color, but it would not really be worth the energy to re-grout it (In my opinion). Although, it's an option to try re-grouting lighter, but don't expect too much. If the tile came out of the box with edges chipped, or surface warped, you may have a warranty claim. You would have to contact the manufacturer if that is the case. Did you DIY this, or hire someone?

Sarah- I was going to suggest discussing the issue with your tile installer, and explaining that you will not accept the product. Some people use payment as recourse.

Normally, the grouting is done with a rubber or plastic float, then sponged down. It would be unusual for any metal tools to be used. It really looks like it was cut, perhaps to try and correct something for straightness? It's plausible a metal tool was used to try to scrape down uneven grout after it was dry.

In any case, if you leave it as is, you may want to place a bead of clear silicone at the countertop so it is a bit more watertight.