Alli vs. Allison

When I was growing up the only time that I was ever called "Allison" was when I was in trouble and most of the time it sounded something like this ALLISON JOOOOOOOO!!!! That was my mother yelling at me!!!  Everyone called me "Alli" including my immediate family, my extended family, & my friends.  I remember one time telling my mom that "Alli" was stupid and I when I got to chose I was going to go by "Allison" when I got older.  But, little did I know back then when I was mad at my mom would it really come true!  When I was filling out my college admission paperwork, job applications, & sorority forms as I was a senior in high school it was weird for me to write down "Allison".  However, it quickly became the name that I would go by for the coming years.  Now, when someone that I don't know calls me "Alli", especially without asking it really bothers me.  There are some people that have asked if it was ok...and I'm probably am not going to tell them no, but I don't shorten anyone's name, not even my patient's names without asking first. 
When I was in Delaware, I had a patient that pretty much just said what ever he was thinking & there were many times that I would have to tell him to quit talking to his wife the way he was.  He was just disrespectful & always had to be right. (Man, I can still picture his face.) One day I was in his room & he asked me a question, and I gave him an answer that he didn't want to hear.  Instantly he got defensive, and addressed me by "Alli".  I'm pretty sure you know how this story went, but he was immediately told that my name was "Allison", and that yes, there are times that I go by "Alli", but he wasn't allowed to call me "Alli" & I turned around and walked out of the room.  He had that open mouth insert foot look on his face & was polite the rest of the day. 
Yesterday while at work, I was giving report and a repiratory therapist, who I have never met before addressed me by "Alli".  She had to look at my name tag that clearly said "Allison" to see what my name was and she still addressed me by "Alli".  I was in a different world and trying to get out of work in time for mass, so I wasn't able to correct her, but had a realized what she said before I answered her question, she too would have gotten the lecture about calling me what my name tag says. I didn't shorten her name from "Jennifer" to "Jenn" when I answered her question, so why is it ok to shorten my name. If she would have asked, I would have told her it was ok to call me "Alli", but I just think it's plain to rude to shorten someone's name when...
a: you don't know the person or just met them
b: you didn't ask if shortening my name is ok
c: I have introduced myself as "Allison"

I just feel like "Alli" is from back when I was younger and people that knew me then are more than welcome to call me "Alli".  My entire family & most of my childhood friends still calls me "Alli", and that is most definitely ok, I even have a few college friends that call me "Alli", but these people know me on different level than one of my peers/patients that has never seen/meet me before.  They know a lot about me & know me on a personal level. Other people that call me "Allison" know me on a personal level as well, but when I first met those people I introduced myself as "Allison", so that is all they know me by.  I kind of feel like I am on my soap box, but this is a huge pet peeve of mine and drives me crazy!