Why the representative is so rude for complaining of a delay?

I ordered two items as one order.

One arrived 2nd business day as I used (2nd day delivery).

The other one was shipped with Fedex Home Delivery and estimation is 4 business day.
This was a nonsense, but I tried to wait.
BTW, on the delivery date, Fedex sent me a delivery exception email because of damage.

So, I called to Dell and the representative said a replacement shipping will be soon.
I expected a special handling because there is no reason to shipping back for this case.
BTW, return # assigned the next day and no progress another two business days, so I called once again.

At this time, the representative made a long hold (> 5min) and then said the replacement order will be approved tomorrow and it will take up to 8 business day + 1 additional day from the assigned date.

I asked her to use the next day shipping for compensating delay.
I also asked this delay seems too much, but she only answered it is the policy.
And then she said the refund is possible.

I asked to add a note to enhance this situation more efficiently.
Refund + rebuying will take 2days, but replacement will take 10 days.
It does not make sense for me.

Amex promotion was expired, so I don't want to buy again after the refund.

She raised her voice and mentioned the policy again.
I said "Do not try to fight with me. You need to make me understand.
I'm asking this to your company, not to you"

I asked again to add a note.

And then finally said "Have a good day!"
But, the phone call hung up without any greeting.
Hang up without a greeting is quite a surprise.