Subway Disappoints

Ok...I used to eat at Subway all the time. The main reason was because I worked next-door to one. However, now I do not eat there very often.
Today, as I was out running errands, I walked by a Subway restaurant and decided... "Hey! I'm Hungry... I may as well eat here."
There was this sign in the window advertising their new Chicken Parmesan sandwich. So, I thought... "Heck Yeah. I'll get that!"
On the other side of that sign was an advert for their new Chicken and Bacon Ranch sandwich.

Long story short. I got the second sandwich.
Though, it was not my choice.
I ordered the Chicken Parmesan.
What I got was the Chicken and Bacon Ranch.
I foresaw this coming as she was making the sandwich and I noticed her using the wrong ingredients.
I was in a pretty good mood, and I did not feel like complaining. After all, the Chicken and Bacon Ranch would be a pretty good choice too.
The problem? The girls working there were badmouthing other customers. That should not be done in front of other customers.

Actually...I do not even care about that.
The only reason I am complaining now is that...
Now that I am home...eating the sandwich...I notice that, not only is it the Chicken and Bacon Ranch....but it also does not have any trace of ranch on it.
It is a boring, bland chicken and bacon sandwich.
Don't get me wrong. I love meat! ...but the meat is dry. There is no sauce of any kind on it.

How annoying!

....my previous comment ("How annoying!") ...reminds me of something.
You could call it a trivia question of sorts, but it is really just a question of grammar.
Anyone want to take a stab at it?

"What part of speech is 'Ouch!' ?"

Submit answers in the form of a comment. Winners will receive an all-expense paid trip to beautiful Absolutely Nowhere!