Problem with remodeled pool.

[Rust95]

I am new to this site and appreciate any help or recommendations you guys have.

Well my pool is about 30 years old and was in good shape. The liner needed changing and one wall was buckled a little from a tree root and the coping was a mess and the concrete deck needed to be replaced.. So we decided to renovate the pool. I found a contractor and he gave me what I felt was a decent price. He started in April and finished the end of June. It seemed he was never there to work on the pool his guys would come and do nothing that is why it took so long. I was promised 3 weeks.
So the pool had one wall needing replacement and the rest were in good shape. While they were working on it one of the good straight walls almost collapsed, they tried to straighten it but it was still a little wavy. They said after the pool was filled it would straighten out. It didn't. There are many other things that occurred during this ordeal that I won't get into.

My question is on the wall that almost fell they took it apart to get it straight. Now after 2 weeks it seems that the seam of the wall where it bolts together has split. The liner has a 1/2 inch indentation that goes from the top to the bottom. that you can really see when the light is on. The contractor says the foam separated. He used 1/8 inch foam so I highly doubt that. Could a wall separate like that after it has been backfilled and all the concrete decking put down. The coping hasn't separated like I think the wall has. And what would be the fix.

This is a long story that I tried to condense so I hope it makes sense. If you have any questions about the work they did please feel free to ask and I have pictures I took during the renovation. I have to put them on here if needed.