I think I need to fire my Pool tech

Hello. I have a Saltwater ingrained pool. it is a new build, probably 6 months old.
I have been having an issue with my pool tech for a while now. At first the ph was around 8 and she kept saying it was fine until I made her test it in front of me and then i had to point out the fact the color was pink and not orange.

So she started checking that and getting it almost right. Now I noticed the Ph is still a little high and the Free Chlorine is off the chart high. I checked the chlorine generator and she has it at 80 on auto so I turned it off to try an lower the free chlorine.

All the others seem to be ideal range.

Now this lady started making it a point to come when I am not here, I am guessing she doesn't want me to question her-so I call her boss and still my pool is out of whack.

The builder of the pool had told me before salt water pools are not hard to maintain and are very cheap, rather than paying 80 buck a month for a tech.

Now I, and her, use the test strips but I am curious if I should invest in a more precise and expensive test kit?
Is it hard to maintain a pool?
I mean if I fire the tech company, I should be able to learn and maintain the pool properly without too much trouble right?

I looked at the card of levels in the chlorine gen box and it has been over 5 weeks at 10 free chlorine and before that it was 5 and fluctuated back and forth between 5-10 all the months prior. It has never been below 5 and from my test strips I believe the proper level is around 3.

Should I add chemical to lower or just turn off the generator and watch for levels to lower then adjust accordingly?

Thanks. I appreciate the help.

Do you recommend any good salt water pool maintenance books for a laymen like me to learn?