it is an overlap liner. Going out there to move the dirt away and turn the water back off now I started it back up this morningThat is a pretty significant crease. It looks like there may be a high spot or the wall is out of the track. Pull back the dirt and see if the wall is in the bottom track, because it doesn't look like the wall is very round in that section, the curve looks off. If the wall is out of track they need to come back and fix it. If this is a high spot then they need to come back and relevel the pool, as it will continue to have downward pressure on the wall. Does the pool have an overlap liner? If so it may be that there is not enough slack in that section and the liner cannot stretch and the weight of the water is pulling down on the wall. They would also need to come out to fix that. Do not put in any more water until you know what you are dealing with.
Upon further reflection, I wish to change my thoughts and apologize for said thoughts. @Teald024 could not be more right above me. This is your hard earned money that they dented. @$#% them if they think its OK. If its on a credit card you can dispute it until it is to your liking.I’m going to “ NOPE!!! , that’s not gonna fly” until a new wall is brought out. You paid for a well installed pool by a professional pool installer.