We recently had our pool refinished and new waterline tile installed and, within a couple weeks, a hairline crack started to appear in the grout above the tile that goes approx 1/3 or a little more around the pool. Our pool contractor has been almost impossible to deal with and does not answer or return most calls. They finally sent someone out to look at it and he was going to come back with a tube of caulk and we told him that since this was a new remodel, we didn't think caulk was a good solution and we wanted the grout repaired. They haven't responded to any other calls since and now we are going to escalate the complaint against their license. The question is what are the best options for repairing this crack? We know the grout color and where they purchased it.

Here is a link that might be useful: Pool Remodel