Do I have Stupid Stamped on my Forehead?

Ok so Friday after work I went to the mall to buy a new coat.

I went into a store and found a pretty great coat, only the zipper was missing the piece that you hold on to to push or pull it. (sorry don't know what that little piece is called)

And that's where the Stupid-fest started. I felt like this sales lady just assumed that I must be the stupidest and most ignorant person alive, and kept making the same assumption over and over again.

Our conversation started something like this:

The zipper is broken on this coat
Oh, no you just need to go slowly, don't rush the zipper
No seriously, the zipper is broken
It's not broken, it works just fine, you only have to go slowly (she proceeds to zip up the jacket - of course she is having trouble because she has nothing to hold on to).
Ok, fine, this zipper is incomplete
There's nothing wrong with this zipper.
Listen, this is not the condition in which you received this coat, there is a piece of it missing.
No no no, there is no problem.
This is not how this zipper started out
the zipper is fine, it works.

So I give up this loosing battle with the lady. I decide to take another tactic:

Do you have another one of this coat? One with a complete zipper.
No sorry this is the last one.
Ok can you call around to other stores please to see if they might have one

Now the woman heaves this huge sigh, and take the coat over to the computer which we are both facing and scans the barcode.
She says to me "No there are no other stores that have this coat".

Now remember that I am facing the computer screen with her, and can see clearly that she is lying through her teeth.

"Actually your computer says that there is one in my size at Fairview, can you call there for me please?"

Another huge sigh, she pulls the catalog out from under her desk and proceeds to call Fairview (doing things as slowly as possible, and it's like I asked her to write up an international peace treaty or something).

She gets off the phone after about 4 minutes and turns to me and says "No sorry they don't have it".
"Your computer clearly says that they do"
"Well it's only updated once a day, so they may have sold it last night or early today"

Finally, she has said something that I will actually believe!

"So what am I going to do, the zipper is broken"
"No no, I told you it's not broken, you just have to go slowly, you can't rush a zipper".

Not this talk again!
I am unbelievably frustrated at this point, so I just exhale sharply and turn around to leave the store.

Now the woman calls out to me - "Maybe I could give you 10% off"
So of course I turn back around.

She takes the coat to ring it up and looks at the tag. Now this coat has already been discounted more than 50% - so she pauses and says "If I give you this discount I will get in trouble".

At this point I resist the urge to say "But the zipper is broken!" and just stare at her.
So she says to me "Ok, Ok I will give you the discount, just give me a second to figure out how I can scan it into the system so I don't get in trouble".
I respond with "Do whatever you've got to do".

In the end I did end up with my coat. But the whole ordeal had me thinking about just how stupid this woman was assuming I was. And how strictly she was sticking to that hypothesis despite the fact that I didn't reinforce her belief.

We were staring at the same zipper, the same computer screen, and yet she insisted on flat out lying to me, over and over again. Somehow magically believing that I would just say "oh, ok".