Legal Question in Construction Law in California

Without reviewing the warranty I can't say for sure, but I would bet it limits your remedies to them repairing it. So I suggest you call them out again and let them repair it. Five cracks, two recurring does not sound like it is so defective that you can get past the warranty and call the pool unrepairable. Only if it is so defective that it cannot be repaired would there be any point in suing anyone.

I somewhat agree with Mr. McCormick, but another possible strategy (if they don't respond to a demand) is to sue them in Small Claims Court for the money value of the repairs they refuse to make (up to $7,500). This is a cheap and sometimes persuasive alternative. I suggest investing in a copy of Everybody's Guide to Small Claims Court in California, published by Nolo Press and widely available.

Both of the above are possible, but I would start with a complaint with the Contractors State License Board and also make a claim against the contractor's license bond. It is quite likely that the company that did the installation is at fault because of improper installation. Expansive soil in particular can exert tremendous pressure if not properly accommodated. I've run into this problem on several occasions. The CSLB also has arbitration programs and in some cases will pay for an expert to assess the problem.