This is Deli with M&M Floors. I wanted to respond to your complaint because it sound to me like you are blaming M&M for your excessive amount of cracked tiles. Please refer to the Tile Council of North America so that you can understand why it is that this happens.
When a tile is installed over a concrete floor different bonding mortars can be used, I am not familiar with your case being that you did not have a full name in your complaint. But let me give you an example:
Typically, we use a high cost anti-fracture mortar for all our new construction builder homes that gives homeowners a warranty on any fracture/cracked tiles. The mortar gives the homeowner a warranty that states that if your subfloor cracks, and the crack does not exceed 1/8"", they will pay us (M&M) for any repairs that we submit claims to them for.
M&M has no control on your subfloor, we are not the ones that pour your slab when your home is built. Most of the time, in new constructions. the concrete slabs are not given the proper time to curate before the tile is actually installed over them. THIS IS NOT OUR FAULT. As a natural process concrete slabs are constantly expanding and contracting, climate changes can cause more of this. As they expand and contract this movement can cause your tiles to crack.
That is the time that we come out and do our best to repair your cracked tiles. We have no control on whether tiles become dropped/discontinued by the manufacturers that make them. We try our best to keep record of the tile that is left over in all the homes we install so that you do have extra tile for repairs. As you mentioned we left you 7 Boxes of extra tile, that is above and beyond what is required of us to leave left over.
I really hope that you understand and read what the Tile Council of America says on this issue, I understand that maybe for lack of better knowledge you feel as if we are the cause of your problems.
I am very sorry that this is happening to your home, if there is anything we can do to make this an easier process please let us know and we would gladly do it at cost for you.