I worked for several years for a civil engineer who specialized in concrete. There are several factors that could be the cause. Pitted, cracking concrete is a result of a poor mix design, as the "recipe" is called or a result of the contractors not following it correctly. Also affecting the results is the drying/curing time and the time of year (climate) it was poured. And if you live in an area where there is a lot of freeze-thaw, it is even more important that the mix design be correct and be followed.
You should consult an engineer who specializes in concrete. If you don't know one, google it in your area or consult a construction company dealing with concrete or a concrete company itself (Lafarge, for example) to find one.
Properly designed, mixed, and poured concrete should last for years. Concrete may also spall, but that is very common and doesn't affect the strength of the concrete.
It also matters what form your poured concrete is in with respect to how critical the pitting/cracking is - is it a driveway or a foundation?
Best to consult a specialist. And read your contract re: warranties, if you have one.
The engineer will take a sample to analyze it and will give you a report which you can then use to sue the ass off the guy who screwed up your concrete. He may also be able to provide you with a remedial mix to fix the problem.