tile floors in newer house continue to crack?

house is 3 years old. floor is raised wood. tiles are spanish type about 16". they are in a diagonal design rather than squared. a year ago I remove rugs to spring clean and there were many cracked edges and several hairline cracks - one continuous over the whole floor. they removed about 13 or 15 tiles and replaced and the tiles didn't match in size exactly so the groutlines looked bad. they added support under the house (it sits high up). They said the subfloor was correct, but I am a senior and alone and didn't know the difference, so had to believe them. Now there are at least 3 cracked through the middle, several hairlines, and some corners in all different areas of the house.

Please tell me your thoughts and how I should proceed - I can't deal with this for another year - last time it dragged out for 4 months and I had missing tile for the summer. I feel ill from this - it is my whole life savings and I've lost $100 on the house as it is.

I just don't feel that they were laid in correctly to begin with. should I get an attorney? will that cost me a lot? I can not afford it.

PS - at least 2 other houses on this block were built at the same time and had the tiles done by the same contractor. they were on concrete, but the houses had to be completely torn out and redone last year due to incorrect subflooring issues. they said mine was different as it is on wood, but its still bad. Please help.