I want to install fibre, but how do you tell

Hi.
With all the scams, both phone and electronic, serveys and the ongoing list of nusance calls and door to door religious and other salespeople going about, there are many reasons not to trust what comes to the door.
For example I have been told by my parents that under no cercumstances should I open the door at all even to a curior because of safety concerns.
Yesterday I was at my aunt’s house, after a salesperson knocked on the door which I did open asking to install fibre.
Like this “hello sir, I have come to install fibre in your house”
Me, I never ordered any.
Man, “we are upgrading your ariea and I need to connect fibre to your house right now.”
I didn’t order it.
Do you live here alone was the next question.
At this point I was shocked, now my dad, a power enginier who has no fear of serveys, and men at the door even going so far as to engage and start a deal, a man coming offering the same thing, wanted to install fibre, and while dad watched it closely what he did, managed to get us a nice fibre connection of which I am using and am thankfull for.
I am not one such man.
I am blind and spam savi.
My responce was to get this guy to fuck off as quickly as I could, manners were out the window.
This guy was obviously a scam, I had no way of knowing if he was truth and with all the horror stories well who knows.
In hindsight, the instal I have been talking about as the connection we currently have there has been shocking.
In fact the way it started with u was that our connection broke and stopped working and the previder basically said I should order fibre.
In this reguard, the previder at my aunt’s address has allready set up a plan for us to confirm of which all I need to do is hit a button and it will just work.
My aunt and other family were quite rood back but that does bring up the situation.
An example can be found here

some guy in a construction vest just tried to get me to switch to Optik fibre, anyone else experience this?
byu/vancouverdev invancouver

There are many horror stories, one of these happened to a friend.
One of my friends had a man come to the house, they botched it completely, the cables were not deep enough, the ceelings were smashed, and they came round at all hours of the night to confirm things worked and to sign off.
My friend complained to the previder and it went up the chain to their boss who got rid of them and handled everything himself and it was happy all round.
My friend got a good deal out of it to.
However, how would you tell.
There is precious material on the dark side of fibre installs even though I tried to search for it.
What I have clearly got from several sites is you need to order it yourself.
So if some random shows up and wants to install it, its probably a scam, but it could be also the company upgrading an ariea so how do you tell.