I am wondering if anyone can give me any advice of my issue.
Had a new pool liner ( top quality one) renewed 3 years ago after removing the last one and ensuring the casing was well. We used a local company, who is well established and recommended. We are down in France about 10 days every month the entire year. We also have a very good garden and pool company who have looked after our pool for 5 years and do a great job. Last month when closing the pool, we discovered about a metre long ripple on one side of the pool and a few smaller ones adjacent on the other wall. I called the company who fitted the pool, who without any testing claimed it is caused because the Ph has been left too low and stated the 15 yr guarantee will not cover it. The company who has looked after the pool, he came and was able to prove with documented records, ever visit he records the Ph and corrects it should it be needed.
My concern is this pool is not left months on end without it being used, it is well regulated and checked, and as it is only 3 yrs old and it’s guarantee state it’s protected against chemicals, etc.
My question is what can I do if the company fitted it has shrugged its shoulder, without any further checking except a visual to determine the issue. I trust our pool guy totally and I’ve a feeling this may be a failure of the liner. But how can I further this with the fitting and supply company that doesn’t want to take it on. Any advice to help greatly appreciated.
My French isn’t good enough to argue the ins and out with the pool company.
Many thanks
This article might help with this problem which is quite common. Few if any installers will accept responsibility for this.
Has this top quality liner a name?
Without seeing the pool very limited chance of giving an useful advice. Ground water can often be the cause, far more than pool water pH which would have to be low for some time (less than pH6.5. )
You have records of the chems the liner installing company do not so they really need to take notice. It may not be their fitting at fault it can be the pool builders. So many (100% to date) do not use a water bar in the construction, this fundamental mistake is behind many issues.
Guess I didn’t give the answer they wanted
Or perhaps not been online since, or any number of other factors.
Yes of course, maybe wait until you can regularly get on line before asking?
Perhaps he did get the information that he was looking for and is acting upon it.
Yes that could also be true, It seems in these modern times the one way flow of information is fine by some. I consider it rude, not to at least reply with a thank you. 
James, you are exactly right.