I'm not sure what to say other than: "kill the mustard algae!".

Your pool is somewhat out of level, but not enough to affect the function of the pool. Some pool owners would never notice, but it would drive others nuts.

Your recourse is going to be governed by the contract.

Unless Waste responds, I'm not sure anyone here would have tried to solve a problem like that.

One possibility: a tapered custom made stainless steel shim. If you design it, any SS (restaurant kitchen) sheet metal shop could make it. I'd guess the cost (if I had it made here) would be in the $1,000 - $2,500 range, not including installation. Whether it's possible for you, depends on how the top of the pool wall is configured. If you want to send me some detail shots of the BACK of the pool wall, from the coping to 6" down on the wall, I can offer a further opinion.

And, one caution: do NOT accept a jury rigged solution, that will 'fix' the appearance, but compromise the durability of the pool.

Good luck.