I'd say dump the pool guy, unless he is a family friend or something, first.

You have unfortunately added a bunch of copper to your pool, that is what is in most "Blue" products, which is a weak sanitizer of algae, no effect on bacteria. It sounds like you already understand that is what is staining your liner.

In regards to the numbers you posted, did you use your Taylor kit to get these? I don't know what "H" of 6.9 is. I have no idea how you get a measurement of 9 ppm for pristine blue, I assume you are testing for chlorine levels, or copper? What I don't see is a chlorine or FC number, or CYA.

Your options are 1: live with the copper in your pool and go back to BBB method 2: sequester the copper using another chemical and go back to BBB method 3: drain and refill and go back to BBB method.

With what sounds like a brand new liner that the pool store guy put in(?), if its his fault and the liner is damaged, have him fix it and pay for the drain and refill. Then go back to BBB method.

As far as going back to the BB method, read the sticky "Super Simple Pool Chemistry: or "Beginners guide to pool care".