How can I improve a poorly executed stamped concrete job? The impressions are barely noticeable and in some spots nonexistent. The pattern ran over into the borders, and chunks of concrete are missing in spots. Also, the grout lines didn't always match up as they moved along, leaving dual tracks instead of one clean grout line. We discussed or dissatisfaction and they have no reply.

I hope they didn't get all their money.

There isn't much you can do short of demolishing the walk and trying again.