My builder hired a substandard concrete contractor. They have been working on my home 6 months and foundation is still not finished. 1 to 3 workers show up for 1 to 3 hours , 1 to 3 days per week. They have left trash on lot the entire time, dumped another 2 - 3 tons. Removed most after I raised sand. Builder does not have any control of contractors. I've been met with months of delays. I have zero confidence in concrete contractor and now builder. There are several defects with the foundation that may be correct, but contractor hasn't made effort to correct. The contract is very vague but says work will be performed in a "Substantial Workmanlike Manner" In my opinion this has not been met.
You can "get out of it" if you and the other side agree in writing to a mutual termination. That's ideal. Otherwise, one party will need to sue the other and the court will decide.