It depends. I can't see it. How much cracking are you experiencing? You will generally get some hairline cracks. Cuts are made into slabs about every 100 square feet or so. That controls the cracks so they occur at the cut.
Suggest you have the building inspector look at the slab. He may not pass it if it is too bad but most don't look at it. Or hire an engineer to look it over and provide specifications that match your soil type, concrete type, and concrete strength. What concrete specifications were called for in your building contract? To convince the contractor to tear it out and start over or to go to court to get relief will both require an expert opinion and one that says he did something wrong or violated the contract.