What was in the specifications? Specs call out classes of appearance, lowest being for covered areas, highest being exposed. Strangely, I recall it has to do with formwork joint offsets. Your concrete looks actually quite good, I would not worry at all. Any concrete contractor will patch larger honeycombs after stripping formwork. This is standard practice.

In the construction contracts I have administrated a contractor is required to make corrections to the work when the need is identified by me or in your case by you. If you have asked for a correction to the work and provided reasonable evidence that it doesn’t conform to the contract or the building code or some other accepted standard (engineers opinion) then the contractor must respond. I’ve never heard of a show down meeting where each side presents their evidence. But if that’s what your lawyer recommends do it Honeycomb can be patched; what needs to be determined is the structural capacity of the work. You’ve not shown us enough for us to comment on that If his engineer says it’s adequqte it’s your turn to present evidence that it’s not. I’m not sure if you need to offer a solution for a correction yet but it might expedite the correction. I once told a construction contract lawyer that I was afraid the other side would counter our position and he said “let them”. Does your contract call for arbitration or mediation?

Did the contract stipulate the removal of the soil/material from the back yard? Look closely. This is pretty important. IF (BIG 'IF') your contract stipulated removal of soil/material from backyard then you have the beginnings of a 'broken contract'. And IF the GC decided to add height to the foundation (from 2ft to 3ft in height) without notice, then yes we are now firmly into the "without notice" blurb in the contract. By the looks of the photos from another build 1 year ago, I would say this firm has lost sight of it's workmanship ratings. Your foundation looks NOTHING LIKE the build from the previous year. Notice in your 'example' photo (from 1 year ago) the earth has been excavated around the EXTERIOR of the foundation wall? That is missing in your build. The ONLY THING I can think of for this, would be the PROPERTY LINES of the other homes are SO CLOSE to your foundation that they CANNOT move the earth...because it isn't your earth to move. Any thoughts on that? Anyway, if you feel like you want to part company with this firm, you will probably want to speak with a lawyer who deals with realty and contractual law in the building sector.

Epoxy grout